Adult kids suspected businessman Stephan Wagner, arrested for allegedly poisoning wife’s tea with insecticide, police say

Stephan Wagner’s adult children uncovered an 18-month plot to kill his wife, police allege, calling them after tracking falling levels in a bottle of Ant-Rid as their mum became “seriously ill”.

• 5@5 BULLETIN: Wife’s tea allegedly poisoned for 18 months

A well-respected businessman accused of a poisoning campaign against his wife was allegedly caught after his children began to track how much pesticide was disappearing when their mother kept falling ill.

Police arrested 61-year-old Stephan Wagner at the home he shared with his wife Glenda on Tuesday, charging him over an alleged 18-month plot to kill his wife Glenda, they say was uncovered by their adult children.

It will be alleged that inside the home they shared for 30 years, Wagner used insecticide Ant-Rid to poison his wife, with police alleging he spiked her tea from Boxing Day 2022 until September 16, 2024, resulting in her becoming “seriously ill”.

Police sources told the Telegraph they will claim Mrs Wagner had suffered lifelong illness from allegedly being poisoned with “repeated doses” of Ant-Rid in her tea - and that it was their children who raised the alarm with police.

After Glenda became unexplainably ill, it’s understood police will allege the couple’s children became suspicious of their father, and began marking the bottle of Ant-Rid to track how much, and when, it was being used.

Stephan Wagner. Picture: Supplied

The insecticide is made with borax, which is toxic to both humans and animals and can lead to death.

The Telegraph can reveal that police will allege Glenda has a lifelong illness as a result of the poisoning.

Officers from Campbelltown City Police Area Command launched Strike Force Southport in September to investigate the alleged poisoning after Mrs Wagner, 66, was hospitalised for several days.

A month later, detectives arrived at the couple’s home in St Andrews and arrested Wagner, also seizing a bottle of insecticide from the property.

The semi-retired IT professional appeared in court on Wednesday, and will remain behind bars on remand for at least the next two months.

He did not apply for bail and it was formally refused during a brief mention of his matter in Campbelltown Local Court on Wednesday.

NEIGHBOURS MYSTIFIED

At the Wagner’s home on Lanark Ave, neighbours told The Telegraph they hadn’t seen Mrs Wagner for a “couple of months”, after her husband told them she had been unwell and was suffering from an “auto-immune disease”.

“I noticed that for a while, the wife was missing, like not getting out of the door. You know, she usually would come here and get the dog around, so I just asked out of neighbourly curiosity, what’s happening,” he said.

He said Wagner told him his wife had an “auto-immune disease” and she had left to “get cured”.

Wagner appeared in Campbelltown Local Court after his arrest. Picture: NSW Police

“He said … she went to Orange to see her sister and stay there and get well. And I mentioned if it is related to Covid. He said, ‘let’s not make assumptions’.”

Wagner, who was charged with cause poison etc to be taken with intention to murder (DV), use poison etc so as to endanger life (DV), and use poison etc so as to inflict grievous bodily harm (DV), “semi-retired” last years, after a long career.

WHO IS WAGNER?

According to his LinkedIn profile, Wagner worked as a regional manager for AusIndustry, the federal government’s department for industry, innovation and science, for almost 10 years before retiring in March 2023.

Prior to that, he was an account manager for IT manufacturing company Ciena for two-and-a-half years, and also lectured part-time at Western Sydney University.

His lengthy career includes stints at Optus, Nokia, Telstra, the CSIRO and the Australian Army, as well as completing an Master of Business Administration in 1997.

In a blurb spruiking his credentials, Wagner wrote “over the past 40 years, Stephan has created significant business success in commercial leadership and senior sales (B2B, wholesale and retail) management roles in the innovation and ICT industries”.

He lists passion for “Australian innovation success” among his key attributes and outlines several multimillion deals he has had a hand in during his working life, including saving Optus $5m in implementing what he refers to as a “network simplification” program.

Investigators search a St Andrews residence as part of Strike Force Southport, launched to probe the alleged tea poisoning. Picture: NSW Police

‘I THOUGHT SHE MIGHT HAVE CANCER’

Another neighbour confirmed a moving truck came by the house of the accused on Tuesday night, and again on Wednesday morning, with what appeared to be the couple’s children taking some items from the home.

The neighbour — who has lived across from the house on and off for more than three decades — recalled Glenda’s health deteriorating over the past six months or so, but believed it was due to her age.

“I thought she might have had cancer or something, and then when about a month ago an ambulance came and took her out on a stretcher, I thought maybe they took her to a hospice or something since she didn’t come back”, she said.

The home appears to have been empty since Stephan Wagner’s arrest.

COURT APPEARANCE

Officers from Campbelltown City Police Area Command launched Strike Force Southport in September to investigate the incident.

Wagner was arrested on Tuesday at the St Andrews home he’s lived in for almost 30 years, where police seized a bottle of insecticide for forensic testing.

According to property searches, Mr Wagner owned the property with his wife, and his children grew up in the home.

Wagner, dressed in a red jumper with a blue collared shirt, appeared on screen in court via video link on Wednesday, and only spoke to confirm his name when asked by the magistrate.

His lawyer, Rylie Hahn-Hamilton from Marsdens Law Group in Campbelltown, declined to comment when approached by media.

The case was adjourned to December for police to begin serving their brief of evidence, while Magistrate Clare Farnan put an apprehended domestic violence order in place prohibiting Wagner from having any contact with his wife.

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Originally published as Adult kids suspected businessman Stephan Wagner, arrested for allegedly poisoning wife’s tea with insecticide, police say