Jo Cox murder: Neighbours say Thomas Mair was a 'loner', far right links feared

London: As Britain searches for answers over its first murder of a female MP, Jo Cox, attention is focused on the alleged killer: 52 year-old Thomas 'Tommy' Mair, a quiet loner whose motives are still a mystery.

But piece by piece, a picture is emerging of a quiet, troubled man with a history of connections to far-right groups. Eyewitnesses reported that he had shouted "Britain first", or "put Britain first" during the attack.

However Britain First, a group of anti-immigration, anti-Islam activists, denied any connection with Mair and condemned the murder.

Neighbours said Mair had lived alone in a council house after the death of his grandmother 20 years ago, 15 minutes' walk from where Cox was killed. He had never married or had children and did not have a job.

British MP Jo Cox's dedication to the voiceless may have cost her her life.Credit: AP

He was described as polite and quiet, regularly seen on his way to use the computers at the library.

"He's the last guy I would have thought of," said one neighbour. "He's just quiet. He kept himself to himself. He lived by himself. He's been on his own for about 20 years."

In a local newspaper interview in 2010, Mair spoke to The Huddersfield Daily Examiner about working as a community volunteer at a park, after being referred to a clinic for adults with mental health problems.

"I can honestly say it has done me more good than all the psychotherapy and medication in the world," he said. "Many people who suffer from mental illness are socially isolated and disconnected from society, feelings of worthlessness are also common, mainly caused by long-term unemployment.

A forensics officer looks at a female shoe, at the scene after Labour MP Jo Cox was killed in an attack in her constituency.Credit: AP

"All these problems are alleviated by doing voluntary work. Getting out of the house and meeting new people is a good thing, but more important in my view is doing physically demanding and useful labour."

His half-brother told The Guardian that Mair volunteered at a special school several times a week and had never expressed racist or even strong political views.

Alleged killer Thomas Mair gave his name as "death to traitors, freedom to Britain" during his court appearance on Saturday.

Another brother said: "I am struggling to believe what has happened. My brother is not violent and is not all that political. I don't even know who he votes for. He has a history of mental illness, but he has had help."

Mair was named as a supporter in an online publication of the pro-apartheid White Rhino Club, Britain's Daily Telegraph reported.

Ten years ago the newsletter published an inquiry about the whereabouts of "Thomas Mair, from Batley in Yorkshire, one of the earliest subscribers and supporters of SA Patriot".

The Southern Poverty Law Centre in the United States, which monitors racist groups, claimed it had evidence Mair had been a "longtime supporter of the neo-Nazi National Alliance", a US-based organisation. They said that in 1999 he bought a manual from the NA that included instructions on how to build a pistol.

Police have said they are not looking for any other suspect.

However the murder has raised new questions over the security of public figures in an age where anger is whipped up on social media.

"Fight against the hatred that killed her," her husband said in a moving statement, hours after Mrs Cox's death.

London's Times newspaper reported that police had been in the process of arranging extra security for her, after a three-month stream of harassing messages.

The "volume and frequency" of abuse had stepped up, a source from her office said. Another man had been cautioned earlier this year over "malicious communications" with Mrs Cox.

Last year, women MPs raised fears about other incidents of stalkers and people with knives and guns – and the danger sometimes posed when meeting constituents with mental health issues.