A former child actor falsely claimed he was molested by Chancellor of the Exchequer Kenneth Clarke during a cash-for-questions TV sting 20 years ago, a court heard.
Ben Fellows, 40, from Birmingham, alleged that the heavyweight politician had plied him with alcohol and carried out the sexual assault in the office of a lobbyist while he was working undercover for ITV's Cook Report in 1994.
In the autumn of 2012, he told national news reporters about the alleged assault and stories were published in print and online, jurors at the Old Bailey were told.
He also said he had been abused by a number of people in the entertainment industry, including a senior female executive at the BBC whom he claimed seduced him when he was aged between 14 and 16, the court heard.
Fellows, who was described as "an inventive and sometimes persuasive fantasist", claimed he been invited to a cocaine-fuelled party on BBC premises hosted by two of Britain's biggest stars of the day, the court heard.
He went on to make a statement to police after being interviewed by officers as part of Operation Fairbank - the high profile investigation into Westminster historic child sex abuse.
But when officers checked out his version of events, they concluded they were false and began treating him as a suspect rather than a victim, the court heard.
Opening Fellows' trial, prosecutor Duncan Atkinson said: "In that witness statement, the defendant said that in 1994, when he was 19 years old, he had been employed as an undercover actor by an investigative journalism programme on ITV, the Cook Report, during a sting operation against Ian Greer, the political lobbyist.
"The focus of that sting operation was a suggested role by Greer in arranging for politicians to ask questions in Parliament in return for money - or cash-for-questions as it was known at the time.
"The defendant said in a witness statement that whilst engaged in that capacity he had been sexually assaulted in Greer's London office by Kenneth Clarke MP.
"He named a number of persons as having been involved in the Cook Report investigation who he said were aware of the assault, which he said had been recorded by a covert video device with which he had been issued."
Mr Atkinson told how police interviewed members of the Cook Report team who said they were all unaware of the allegation.
At the time, Mr Clarke was Chancellor of the Exchequer, so it would have been front page news, they said.
They had not seen a video showing abuse and none of them recalled Mr Clarke even being in the lobbyist's office.
After Fellows was arrested, he insisted the allegations were true saying the Cook Report staff were too afraid of losing their jobs or "falling foul of the establishment" to corroborate them, Mr Atkinson said.
He also claimed he was subject to intimidation and threats as a result of having spoken out.
In October 2012, Fellows was interviewed by journalist Jack Malvern from the Times newspaper.
Fellows told him the story about Mr Clarke and made a series of other allegations which the reporter found "troubling" when he tried to check them out.
For example, he discovered at the time the trained actor said he had been seduced by a BBC executive he was 19 and not 14 as he had said.
He also found inaccuracies in his claims about his time at the Sylvia Young Theatre School and as a result of his checks, no story was published in the Times.
However, the Express ran two stories in October 2012 headlined Sex abuse rife at the BBC says Ben Fellows and My hell with Britain's biggest stars says Ben Fellows, without naming names.
Meanwhile, Fellows published an internet article himself with an account of his interview with Mr Malvern alleging that the Times was seeking to protect those he had named.
The defendant, of Redstone Farm Road, Olton, Solihull, denies perverting the course of justice between November 14 2012 and December 1 2012.
The trial continues.