A local radio station has been besieged by a pirate who repeatedly keeps hijacking the airwaves to play a song about a masturbation.

The Winker’s Song, an explicit 1970’s tune by Ivor Biggun, has been illegally broadcast on Nottinghamshire station Mansfield 103.2 on eight separate occasions over the last month.

Now, broadcasting watchdog Ofcom has launched an investigation to identify the culprit – who is believed to be using a small transmitter to override the station on the same frequency.

The song, which features the word ‘rocket polisher’ 36 times, was most recently played during a live family broadcast at Mansfield’s Party In the Market last weekend.

Tony Delahunty, the managing director of Mansfield 103.2, told BBC Radio 4: “Some people have told me that their children have started humming the song in the car. We have had calls from people who have found it hilarious, while some have raised their concerns, including our competitors, and a lot of people in the industry are aghast at how hard it is to stop these people.”

He added: “We are told by Ofcom who are investigating the matter, that you only need, and this is the frightening thing, a small transmitter and if you can get near where there is an outside broadcast or a signal and you can overpower that signal [and] you’re on the airwaves.”

Ofcom are yet to track down the mysterious pirate, but have warned that malicious radio interference is a criminal offence that carries a potential sentence of two years imprisonment and an unlimited fine.