A 999 call handler has been awarded £11,000 after a tracking device was secretly fitted to her car to monitor her while she was on sick leave from West Yorkshire Fire and Rescue Service.

Anthea Orchard was off work with stress when she discovered a private investigator had been hired by West Yorkshire Fire and Rescue to check whether she was moonlighting.

The married mother-of-two said she witnessed men hiding in cars outside her home, received mysterious job offers and found a GPS tracker had been fixed to the underside of her Audi.

The 35-year-old was signed off work by a doctor with stress and hyperthyroidism last November, soon after returning from 12 months’ maternity leave.

West Yorkshire Fire and Rescue employed a private investigator to spy on her after her bosses suspected that she was working full-time running a business connected with her hobby of balloon-making, she said.

Mrs Orchard, who lives with her husband Gareth, and children Ashleigh, five, and  Haydn, two, said she kept getting phone calls from people purportedly offering her work, which she turned down, telling them she was signed off work.

However, she traced the number and discovered it was a private investigator, she said.

“This is an infringement into my family life,” she said. “The whole situation has made me very ill. It is not right that public money is being used in this way.

“The car is in my name, but it was also used by my husband. One of my children was just a baby when this surveillance started.”

Mrs Orchard said she has suffered depression and has spent £300 on blinds for her house because she feels like she is being watched.

Mrs Orchard was exonerated by the investigation.

She has now left her job with an £11,000 pay-off after signing a “compromise agreement” in which she agreed not to take the service to court for human rights violations over “unnecessary surveillance or invasion into privacy and family life”.

West Yorkshire Fire and Rescue declined to comment on the case.

Fire Brigades Union brigade secretary for West Yorkshire David Williams said that he knows of at least one other case where similar tactics have been used against a West Yorkshire Fire and Rescue employee.

However, he said he could not establish how widespread the practice is because the investigation fees do not appear in the organisation’s accounts.

“It’s like something from a James Bond film,” he said. “It beggars belief.”

“We’ve got no idea how much it’s cost. It’s real cloak-and-dagger stuff.”

He said a firefighter had been subjected to a “similar” investigation after taking on “above-board” secondary employment on his days off - which is permitted - but failing to officially notify bosses.

“I should imagine it was exactly the same scenario,” Mr Williams said, adding that the case is going through an employment tribunal.

“It just breaks down morale. People are frightened to take days off - they’re coming in sick.”

He said it was difficult to say whether other brigades used the same methods.

“I don’t know if our managers are more ’robust’ in investigations than others,” he added.