In a letter to The Times, Nigel Seed QC said it was a lack of evidence that stopped the case against Myra Forde.
He said she intended to allege that she had provided rent boys to Sir Edward, but she has denied this was her plan.
Gloucestershire and Thames Valley forces are the latest to say they have received information about Sir Edward.
Thames Valley Police said the information it is investigating was received following media coverage about the historical allegations made against Sir Edward.
Gloucestershire Constabulary said the claim they received has been referred to Operation Hydrant, which is overseeing police inquiries into historical child sexual abuse.
The Metropolitan, Wiltshire, Hampshire, Jersey and Kent forces are conducting separate inquiries into the late MP.
Forde's ex-lawyer, Richard Griffiths, said on Wednesday that she did not state that Sir Edward was a client, nor did she threaten to expose him if the prosecution against her was continued.
On Monday, the Independent Police Complaints Commission said it would look at whether a case was dropped by Wiltshire Police when a person involved made claims against Sir Edward.
Mr Seed, who now sits as a judge, told the newspaper there was a large number of reporters at court because Forde had let it be known that she would make the claims against Sir Edward, should the case proceed.
He said two of the three prosecution witnesses failed to attend court and the third refused to leave her cell to give evidence, which prompted the decision to drop the case.
"The decision for the case to proceed no further was mine and was based on the lack of evidence and had nothing whatsoever to do with any potential allegations against Edward Heath," Mr Seed said.
Forde was later convicted of controlling prostitutes after a successful prosecution and jailed for six years.
She was prosecuted and jailed again 14 years later for inciting prostitution.
Sir Edward, who was Conservative prime minister from 1970 to 1974, died aged 89 in 2005 at his home in Salisbury.
An allegation about ex-PM Edward Heath was not the reason why a case against a brothel keeper in the 1990s was halted, the case's prosecutor has said.