A semi-retired businessman who spends one day a week alone at his office has been left baffled by gaga radio rules after being told he needed a licence to listen to music.

Dick Robson, 75, was repeatedly warned by the Performing Right Society (PRS) to get a licence if he wanted to play the radio to his staff in his Linton office – despite the fact he has no staff.

Mr Robson, who owns PUK Filtration, said: "The business used to be bigger, but I’ve retired now really. It’s more or less just a hobby. I come into the office once a week, perhaps."

Mr Robson, of Bearsted, happened to be listening to Classic FM, when he received a cold call from the PRS.

He said: "The lady didn’t seem to want to listen to me. She said she could hear the radio on in the background."

Two weeks later, the same woman rang again and Mr Robson received a follow-up letter. He wrote back explaining the situation, but has since received three copies of the first letter.

He said: "I don’t know why they’re picking on a poor old guy like me. None of the other offices here have received anything from them."

However, a spokesman for the PRS has now confirmed: "Mr Robson does not need a licence. We are sorry we have bothered him and a manager will be calling him personally to apologise."

A licence is required wherever recorded music is played publicly, and are graded according to the size of the premises, its type and the number of people listening.

An average fee is 7.5p per half-hour of listening, per unit of 25 workers per day.