The godson of Sir Edward Heath has called for an official inquiry into police handling of child sex abuse allegations against the former prime minister.

Lincoln Seligman said he believes there were serious flaws in Operation Conifer, which has investigated claims against the former Conservative leader for the past two years.

He spoke as reports at the weekend claimed Wiltshire Police, which conducted the £1.5 million investigation, believed it would have had enough grounds to interview the late politician under caution if he was still alive.

Mr Seligman, an artist who knew Sir Edward for more than 50 years from childhood, said Wiltshire chief constable Mike Veale was "acting as judge and jury and has already convicted the man".

Mr Seligman told the Press Association: "My suspicion is that we will learn nothing from the report except innuendo and that really takes nobody any further forward, except it leaves a dark stain over a man who can't defend himself.

"What we are looking for is a judge-led review of a: how the police have conducted Operation Conifer and b: all the evidence it has produced.

"We want a judge to look at that who will be independent and impartial and to me that is the opposite of cover-up, because we want the truth and we believe the truth will exonerate him (Sir Edward)."

Sir Edward, who led the Conservative government from 1970 to 1974, stepped down as an MP at the 2001 general election and died at home in Salisbury in July 2005, aged 89.

Operation Conifer was launched in 2015 after he was named as a suspect in an investigation into historical child sex abuse.

Wiltshire Police will make public on October 5 the "summary closure report" of its inquiry into Sir Edward.

The findings will be passed to the Independent Inquiry Into Child Sexual Abuse, which is being chaired by Professor Alexis Jay.

Last year, the probe found no evidence that a prosecution against a brothel keeper was dropped because of threats to allege publicly that Sir Edward had been involved in sexual offences.

In November a report by Dr Rachel Hoskins, who was enlisted by detectives to examine Op Conifer evidence, was revealed.

Writing in The Mail On Sunday in November, she said she had "exposed a catalogue of fabrication" at the heart of the probe and warned the force it should immediately end its investigation into a key accuser's "pernicious" claims of satanic ritual abuse.

The leading criminologist also branded the inquiry "a disgrace" and said that, while the force had accepted her report, she had "little confidence" police would pass the findings on to MPs.

On Sunday, the same paper reported that claims against Sir Edward include allegations of sexual assault on boys aged as young as 11, including a rape, which would have been enough to have him arrested and interviewed.

In September Mr Veale said Operation Conifer had "followed and complied with national guidance from the outset and throughout" and urged people not to speculate about the report's findings.

Mr Seligman, whose father was a university friend of Sir Edward's, said he had been prevented by police from attending the report's release on Thursday.

He added: "I'm not naive about these things. I think it would have been so difficult for him to hide anything, because he was constantly surrounded by protection officers, secretaries, his general household, that he just wouldn't have had the opportunity.

"But quite honestly, me protesting his innocence is not as important as putting right the injustice that has been done, in my view."

He compared Conifer to Operation Midland, which investigated claims of a paedophile ring among MPs but was later discredited.

He said: "I think the Conifer inquiry must have begun before Midland ended but they seem to have learned nothing about being credulous when it comes to stories from seriously unbalanced people."