A case against a brothel madam living in Kilburn was dropped by police after she threatened to name former Prime Minister Sir Edward Heath as paedophile, it has been claimed.

The allegation was made today after five police forces announced they were investigating child sex claims involving the Conservative politician who died in 2005.

Filipino Myra Ling-Ling Forde, is claimed to have been due to stand trial in the 1990s for running a brothel, but the case was allegedly dropped when she said she would name Sir Edward.

Forde was later convicted on two separate occasions of offences related to running a brothel from a residential property in Salisbury.

The scope of police scrutiny widened after an investigation was launched into an alleged cover-up of a claim against Sir Edward.

Detectives in Wiltshire, London, Kent, Jersey and Hampshire are looking into abuse allegations linked to him.

He became the most high-profile figure linked to historical paedophile allegations on Monday when the police watchdog announced an inquiry into allegations that a prosecution was shelved after a threat was made to “expose” him.

Scotland Yard has refused to confirm suggestions that Sir Edward is being looked at as part of Operation Midland, a Scotland Yard inquiry into claims a VIP paedophile ring operated in the 1970s and 1980s.

Midland is part of a wider umbrella of investigations by Scotland Yard, dubbed Operation Fairbank, into allegations of abuse involving senior politicians and high-profile figures.

A man, now aged in his 60s, claimed he was raped at the age of 12 by the Conservative MP in 1961 but was branded “a liar and a fantasist” when he reported it to social workers two months later.

A Metropolitan Police spokesman said: “In April 2015 an allegation of rape was made to the Metropolitan Police Service (MPS). An officer from Operation Fairbank interviewed the complainant that same month and obtained a full account. Support services were offered.

“However, after a full assessment of the allegation there were no lines of inquiry that could proportionately be pursued by the MPS.”

He said the force was not prepared to discuss why that decision had been taken.

The States of Jersey Police confirmed the former prime minister features in Operation Whistle, an inquiry into alleged historical abuse on the island.

Later, Kent Police said they had received a report on Tuesday of a sexual assault in the east of the county in the 1960s.

Wiltshire Police said its officers and the NSPCC had received “a number of calls” following appeals for potential victims and those with information to come forward.

Former friends and colleagues of Sir Edward have rallied to his defence.

The Sir Edward Heath Charitable Foundation said: “We welcome the investigation by Wiltshire Police, which we wholeheartedly believe will clear Sir Edward’s name and we will co-operate fully with the police in their inquiries.”

Sir Edward, who led the Conservative government between 1970 and 1974, never married and was famously reticent about his private life.

One biographer concluded that he may have been a latent or repressed homosexual while another thought he was “pretty well sexless”. He died at home in Salisbury aged 89 in July 2005.