Congressman Matt Gaetz, a close ally of Donald Trump, denies he had sexual relationship with an underage girl

US politics has been rocked by the revelation that a close ally of Donald Trump is under investigation for allegedly having sex with a minor.

The United States was rocked this week by the news that a sitting member of Congress is under investigation for allegedly having a sexual relationship with an underage girl.

The Congressman in question, 38-year-old Republican Matt Gaetz, represents Florida’s first congressional district in the House of Representatives.

Mr Gaetz is the equivalent of a backbencher in Australia’s parliament, so if you don’t know who he is, worry not. Here is a quick crash course.

A close ally of former president Donald Trump, Mr Gaetz quickly became a star figure in right-wing circles after winning his seat in 2017. He built his profile by railing against “cancel culture”, social media “censorship” and other issues dear to Republican voters.

Few elected officials in the US have been as fiercely loyal to Mr Trump. When the former president was impeached for a second time over his role in “inciting” the Capitol riot, Mr Gaetz led an effort to punish Republicans who voted against him, feuding with the party’s third-highest ranked member in the House, Liz Cheney.

More recently, he has reportedly considered quitting Congress to become a media personality at the pro-Trump network Newsmax.

The chances of that actually happening, however, plummeted on Tuesday when The New York Times revealed Mr Gaetz was being investigated by the US Justice Department (DOJ).

RELATED: Trump plans revenge against pro-impeachment Republicans

Congressman Matt Gaetz speaking at the Republican National Convention during last year’s election campaign. Picture: RNC/AFP

“Investigators are examining whether Mr Gaetz violated federal sex trafficking laws,” the newspaper reported.

“A variety of federal statutes make it illegal to induce someone under 18 to travel over state lines to engage in sex for money or something of value. The Justice Department regularly prosecutes such cases, and offenders often receive severe sentences.”

The investigation started late last year, when Mr Trump was still president and the attorney-general was Republican William Barr.

It’s examining whether Mr Gaetz had a relationship with a 17-year-old girl, and whether he paid for her to travel with him.

The Congressman denies any wrongdoing. Reacting to The Times’ report, Mr Gaetz suggested someone was trying to paint his “generosity to ex-girlfriends” as something “more untoward”.

“I have definitely, in my single days, provided for women I’ve dated,” he told Axios after news of the investigation broke.

“You know, I’ve paid for flights, for hotel rooms. I’ve been, you know, generous as a partner. I think someone is trying to make that look criminal when it is not.”

He said he was “absolutely” confident none of the women were underage.

Adding another significant wrinkle to the story, Mr Gaetz went on to claim he was the victim of an extortion plot.

“Over the past several weeks my family and I have been victims of an organised criminal extortion involving a former Department of Justice official seeking $US25 million while threatening to smear my name,” he said.

“I demand the DOJ immediately release the tapes, made at their direction, which implicate their former colleague in crimes against me based on false allegations.”

Mr Gaetz told The Times he and his father, Don Gaetz, had been approached by people saying they could make the investigation “go away”.

In January, Mr Gaetz travelled to Liz Cheney’s district in Wyoming, urging voters there to get rid of her. Picture: Michael Ciaglo/Getty Images/AFP

He expanded on the extortion claim during an interview with Fox News on Tuesday night, saying his father had received a text in March “wherein a person demanded $25 million in exchange for making horrible sex trafficking allegations against me go away”.

“I know that there was a demand for money in exchange for a commitment that he could make this investigation go away, along with his co-conspirators,” Mr Gaetz said.

“They even claimed to have specific connections inside the Biden White House. I don’t know if that’s true, they were promising that Joe Biden would pardon me. Obviously I don’t need a pardon.”

The interview took a weird turn from there, in a moment that baffled the program’s host, Tucker Carlson.

“You and I went to dinner about two years ago. Your wife was there, and I brought a friend of mine. You’ll remember her,” Mr Gaetz told him.

“And she was actually threatened by the FBI, told that if she wouldn’t cop to the fact that somehow I was involved in some pay-for-play scheme that she could face trouble.

“So I do believe there are people at the Department of Justice who are trying to smear me. You know, providing for flights and hotel rooms for people that you’re dating who are of legal age is not a crime.”

Carlson, confused, told Mr Gaetz he did not remember “the woman you’re speaking of or the context at all”.

“That was one of the weirdest interviews I’ve ever conducted,” he remarked to his viewers afterwards.

LOL Matt Gaetz tries to bring Tucker Carlson into the conversation, says 'you'll remember her,' and Tucker is not having any of it. pic.twitter.com/0XpmTm9yJm

— Josh Jordan (@NumbersMuncher) March 31, 2021

That catches you up through to the end of Tuesday. But in the days since, we have learned even more about the investigation into Mr Gaetz.

It’s actually part of a larger investigation involving one of the Congressman’s political allies, a Florida tax collector named Joel Greenberg.

Mr Greenberg is currently in prison for violating his bail conditions. He has been charged with various offences, including sex trafficking of a minor.

Today The Daily Beast reported that, in January of 2020, US Secret Service agents received information that Mr Gaetz had accompanied Mr Greenberg on a night-time visit to a government office, where the latter was allegedly making fake IDs.

Surveillance footage captured Mr Greenberg and another man visiting the office in Lake Mary, Florida in 2018. When an employee entered the office the following morning, she found the alarm had not been set and drivers’ licences were scattered across a desk.

She reviewed the surveillance footage and then alerted her boss, who proceeded to text Mr Greenberg.

“Did you happen to visit the Lake Mary office on the weekend?” the boss asked.

“Yes I was showing Congressman Gaetz what our operation looked like. Did I leave something on?” Mr Greenberg replied.

The Secret Service discovered the texts while investigating Mr Greenberg, which led law enforcement to look at Mr Gaetz as well.

NEW: The Daily Beast has viewed text messages that got the feds interested in looking into Rep. Matt Gaetzhttps://t.co/UtgjkIwdbz

— The Daily Beast (@thedailybeast) April 2, 2021

On Thursday, The Times expanded on its initial reporting, revealing the DOJ investigation was focusing on Mr Gaetz and Mr Greenberg’s involvement with “multiple women who were recruited online for sex and received cash payments”.

“Investigators believe Joel Greenberg initially met the women through websites that connect people who go on dates in exchange for gifts, fine dining, travel and allowances, according to three people with knowledge of the encounters,” it reported.

“Mr Greenberg introduced the women to Mr Gaetz, who also had sex with them, the people said.”

The paper said it had reviewed receipts from Cash App and Apple Pay showing payments from the two men to one of the women.

In a fresh statement, Mr Gaetz’s office said he “has never paid for sex” and “refutes all the disgusting allegations completely”.

This story keeps getting worse and worse for Matt Gaetz. https://t.co/Y81UW4adYq

— Molly Jong-Fast🏡 (@MollyJongFast) April 2, 2021

Meanwhile, there have been broader revelations about Mr Gaetz’s alleged conduct as a member of Congress.

On Thursday night, CNN reported Mr Gaetz had a reputation among his colleagues for “bragging about his sexual escapades”.

“Gaetz allegedly showed off to other lawmakers photos and videos of nude women he said he had slept with, including while on the House floor,” it said.

“The sources, including two people directly shown the material, said Gaetz displayed the images of women on his phone and talked about having sex with them. One of the videos showed a naked woman with a hula hoop.”

House Speaker Nancy Pelosi, a Democrat, has said the Ethics Committee should look into the allegations against Mr Gaetz, though she stopped short of calling for him to resign.

“If in fact these allegations are true, of course being removed from the Judiciary Committee is the least that could be done,” Ms Pelosi said.

“From what we’ve heard so far, this would be a matter for the Ethics Committee.”

The committee is comprised of five members of each party, and has the power to recommend certain punishments, including expulsion from Congress. For expulsion to happen, however, it would require the support of a two-thirds majority in the House.