A cancer survivor on sick leave was spied on by private detectives and sacked when his company deemed a video of him passing a hose pipe to a friend was evidence of 'physical activity'.
Alan Jones, 55, was the fifth generation of his family to work for major north west glass production company Pilkington, joining in 1983.
An employment tribunal in Manchester ruled last year he was unfairly dismissed after being filmed wearing work boots and helping a friend water some flowers.
Father-of-three Mr Jones also won his claims for disability discrimination and breach of contract at the tribunal, which published its judgment last week.
According to court documents, an unnamed Pilkington employee reported seeing Mr Jones in a local cycle shop wearing heavy duty work boots - and a private detective firm called 'Mike India 5' was hired.
The investigators were paid £950 a day for four days in May 2019 to spy on him, the tribunal heard.
He was called in for a meeting in July, but was not told about the surveillance.
Mr Jones remained oblivious to the sting until he was handed stills from the footage at a disciplinary meeting in September, the tribunal heard.
In one video, Mr Jones is seen in a van with his friend, who was delivering potatoes to nearby houses, and can be seen holding a 'small plastic bag' which appeared to be a retail-sized bag of potatoes.
Another clip shows him and his friend in a greenhouse standing near a tap passing a hose to a farmer, who was watering flowers to be used at Mr Jones' daughter's wedding.
Speaking after the tribunal after the judgement was published, Alan, from St Helens, said: "I was just going to my friend's house. In one of the other videos I was going to the job centre.
"I was shocked when I found out they had hired a private detective. Drug dealers don’t get put under this much surveillance.
"It's wrong what they have done. They even did background checks on me, they looked into my mortgage and how much my house is worth.
"I felt as if it was an invasion of my privacy. It should be against the law. To do this to someone who has worked for the company for 36 years with an unblemished record is outrageous.
"I have never had a day off sick or been late to work. I felt like they were trying to entrap me. It felt like a witch hunt.
"They thought it was all justified. When I tell people, they can't believe it. It feels like they don't think I am telling the truth."
He added: "When I am at the farm I wear my work boots. They are slip-on boots and I struggle to tie my laces. I can slip in and out of them easily if I'm outside and coming into their house for dinner or a cup of tea.
"I was wearing a rugby top too but that doesn’t mean I was going to play rugby."
The tribunal heard the father-of-three was treated with high levels of radiotherapy in the 1980s after being diagnosed with Hodgkin's Lymphoma at the age of 21.
Over the years he began suffering with shoulder pain and, in 2019, this was diagnosed as fibrosis radiation syndrome, a condition that has irreversibly weakened the muscles in his right arm.
He initially took on lighter duties at Pilkington but went on long term sickness absence from November 2018 because of the pain.
While on leave, Mr Jones also began to suffer with depression and anxiety and was referred to local mental health services for counselling.
By March 2019, bosses at Pilkington became convinced Mr Jones, a team leader, was working a second job while on sickness leave - which was against the company's sick policy.
Giving the tribunal's ruling, employment judge Alan Johnson said: "The Tribunal does find it surprising that a more nuanced and measured approach was not considered when commencing this investigation.
"After all, this sort of activity does involve interference with human rights and an individual's reasonable expectation of privacy. An employer should naturally carry out these activities in a limited, necessary and proportionate way.”
The tribunal accepted the surveillance was 'rarely used' and heard the company would be more 'careful' when using private security firms again.
Judge Johnson said although Pilkington was 'understandably alarmed' to hear Mr Jones may have had a second job, they had 'insufficient evidence' to find Alan was guilty of gross misconduct.
He added: "As is often the case with video surveillance, there was a failure to question what could be seen in the video and to ensure that what they suspected might be happening was actually the case."
A hearing to decide on any financial settlement will take place in May.
