Jonathon Canavon, 32, bought the spy camera - disguised as an air freshener - and placed it in the women's cubicle at the BP oil refinery on the Isle of Grain.
Canavon had hidden the device in the ladies' to spy on workmates at the plant, which provides fuel for planes at Gatwick and Heathrow airports.
Pervert Jonathon Canavon pleaded guilty to voyeurism
But his perverted actions were discovered by a woman who spotted the freshener on a pipe while she was in the toilet and saw a blue light flashing. She picked it up and found the camera inside.
After accessing the memory card and viewing it, she was horrified to discover images of Canavon placing the device inside the cubicle.
The woman was sickened when she realised Canavon, who she had considered a friend, had been spying on her and another woman who worked at the refinery.
Canavon was arrested when he arrived on the site for his night shift later that day.
He was charged with voyeurism and theft after bosses discovered he had been using the company credit card to purchase the camera plus "extras" at strip clubs in Essex and London. Canavon was later sacked by BP.
Jonathon Canavon spied on colleagues at the BP oil refinery on the Isle of Grain
As Medway magistrates sent him to the crown court for sentencing, one of his two victims – both in their 30s and who we are not naming – spoke exclusively of her ordeal.
She said: "I was sickened when I realised what he'd done - I thought he was a friend, I trusted him.
"I could have killed him when I realised it was him. The toilet is one place that should be private. It was disgusting to find out he'd been filming us.
"He used to make us tea all day long, so I guess he was doing that so we would use the toilet more. It's disgusting..." - one of Jonathon Canavon's former colleagues and victims
"I felt violated and angry. I didn't know if he had uploaded what he had filmed to the internet. It was months before the police told us they had found no evidence that he had. I think he's just sick in the head.
"We trusted him before this happened. He had been single and lived with his mum and dad and so we even tried to help find a girlfriend, set him up on dates and things like that. We went out on work nights out too."
Canavon had also used the company credit card to buy other covert cameras - one disguised in a tissue box and another as a coat hook - but those have never been found.
The other victim said: "He was one of the gang. He acted nicely towards to us but now I think back, he never ever looked me in the eye.
"He used to make us tea all day long, so I guess he was doing that so we would use the toilet more. It's disgusting.
"It's been horrible, I got depressed over it and felt so violated. I was a mess of emotions, not knowing if he'd put me on the internet or had he given the images to someone else."
Voyeur Jonathon Canavon spied on colleagues with a camera hidden in an air freshener like this one
She added: "I had no control over it. I was crying all the time. I can't go in any public toilet now without searching it first. I have to have a good look around and it always reminds me of what he did.
"I would like to see him put on the sex offenders' register and go to prison for what he has done as we totally trusted him.
"We've both had a huge amount of support been from our other colleagues and bosses and our families, but I really hope he suffers for what he's done."
Canavon pleaded guilty to the voyeurism charge at a hearing at Medway Magistrates' Court in December and also admitted 19 counts of theft by employee when he appeared again this week.
Medway Magistrates' Court in Chatham
Debbie Jones, prosecuting, said: "He was suspended from his post as supervisor at BP when he was arrested for voyeurism and when bosses checked the Amex purchase card, they found it had been used a number of times between October 2012 and May 2013."
He spent about £9,000 at the strip clubs and on the camera equipment.
Magistrates sent the case to Maidstone Crown Court for sentencing on January 31. He was granted bail.
His parents Michael and Marion Canavon have both served as ward councillors for the Labour party in Essex and his father was also a political assistant to the Labour party until last year.
Canavon, of Chestnut Avenue, Grays, Essex, also tried to become a local councillor in Essex in 2004, when he stood as a candidate in East Tilbury area, but was never elected.
Stories you might have missed