People who go to a car park at night for illicit sex are being targeted by robbers because they believe their victims will be too embarrassed to report the crime, according to Barnet police.

Detective Chief Inspector Dick Henson said he believed attacks on gay men and doggers' heterosexuals who congregate in car parks either to have sex in front of strangers or to watch others having sex in the Scratchwood Open Space car park in Mill Hill were going unreported.

His team has posted messages on web sites such as Swinging Heaven, asking people to report attacks and stressing that police are not interested in the doggers' themselves.

Scratchwood, off the A1 north of Apex Corner, is listed by Swinging Heaven as one of London's top four dogging' spots. Det Chief Insp Henson said: "The muggers feel people are vulnerable because they would be reluctant to report it.

"We think there are people who have been attacked but haven't come forward.

"There seems to be a reluctance of the public to admit to having been the victims of crimes maybe they don't want their friends or family to know what activities they were engaged in."

He said Scratchwood has seen intermittent attacks during the four years he has been at Barnet police.

But it has not discouraged people from going there. Last Saturday afternoon there were about ten lone men waiting in their cars in the hope of a casual encounter. At midnight there was a steady stream of people driving in and out of the car park, with about 15 in the car park at any one time.

Men in the car park said attacks were rare but that people should take care.

One man said he had been threatened by three men in a car, who shouted at him and tried to block his vehicle from leaving.

Det Chief Insp Henson said that police were not interested in arresting doggers' or gay men cruising the car park unless they fall foul of public sex laws by causing someone serious offence.

He said police had successfully prosecuted Scratchwood muggers and said victims had nothing to fear from police.

"If anyone becomes the victim of crime we will treat them with courtesy, sensitivity and discretion," he said.

Former Premiership footballer Stan Collymore was sacked from his pundit role at the BBC last Tuesday (March 2) after revelations he was a 'dogging' enthusiast.