He wore a designer tracksuit top, zipped to his throat, and a wary expression. This was 'Witness A', whose identity as an alleged victim is protected by the Sexual Offences Act.
To breach his anonymity is to invite prosecution and potential imprisonment. You might come to think that is what he deserves himself.
For in the course of a two-hour conversation with the Mail, Witness A made a series of disturbing and sometimes sensational allegations. They concerned the senior public figures he claimed to have met and had sex with while working as a teenage prostitute in the 1970s and 1980s.
As he talked, his gaze often slid away from scrutiny. He is a liar by habit.
But at least one of his statements had the ring of authenticity — and it goes to the heart of a scandal that raises profound questions about the leadership and priorities of the Metropolitan Police.
For in the course of a two-hour conversation with the Mail, Witness A made a series of disturbing and sometimes sensational allegations
'The police wanted me to join up the dots in the Harvey Proctor case,' said Witness A, who has never spoken publicly before.
'They realised their investigation [into him] wasn't going anywhere. 'So . . .they wanted me to say Harvey Proctor did this and that, and that I saw him [do it]. They wanted me to implicate him.'
And implicate Proctor — and others — Witness A obligingly did, in interviews with detectives from Operation Midland, the disastrous Metropolitan Police investigation into an alleged VIP paedophile ring.
The extraordinary story of Witness A and another fraudster known as Witness B, which we can tell today, suggests they are somehow above the law, despite a former High Court judge demanding they face prosecution.
For although both witnesses told a tissue of lies that could have led to innocent men being jailed for life, neither of them has been held to account.
Unlike the fantasist Carl Beech, whose sex abuse lies lay at the heart of Operation Midland, neither has been charged with perverting the course of justice.
A decision not to launch a criminal investigation into their testimonies was made behind closed doors by the Met — the same force that entertained them as witnesses. But it has never publicly explained why.
Could it be that the Metropolitan Police, ashamed of its own mistakes, has been operating a two-tier justice system?
As the Met begins to investigate alleged breaches of Covid regulations at No 10, fresh question marks have emerged over the judgment of the Commissioner who launched the controversial probe.
THE CHARGE SHEET OF COMMISSIONER CALAMITY
Only four months have passed since Dame Cressida Dick was granted a two-year extension to her contract.
Her determination to carry on had received strong backing from London's Labour Mayor Sadiq Khan and Lord (Ian) Blair, the former Commissioner and serial bungler who resigned from his post after disagreements with then London Mayor Boris Johnson in 2008.
But many people questioned the extension because of the number of blunders and scandals that have increasingly marked Dick's career at the top.
There were calls for her head in 2005, when she was 'Gold Commander' in charge of the disastrous Met operation in which innocent electrician Jean Charles de Menezes was shot dead on a Tube train after he was mistaken for a terrorist.
Only four months have passed since Dame Cressida Dick was granted a two-year extension to her contract
More recently, as Commissioner, she has been caught up in a string of controversies including her force's woeful security operation at the Euro 2020 final, and allegations of a 'cover-up culture' at Scotland Yard.
Last June, an official report branded her force 'institutionally corrupt' and accused her of trying to thwart an inquiry into the murder of private eye Daniel Morgan. She has rejected the key findings.
Last October, she faced a clamour to resign after she admitted that Sarah Everard's murder had corroded trust in the police and brought 'shame' on her force.
And in what was described as Scotland Yard's 'darkest day', a string of MPs, including the chair of the women and equalities select committee, said she should go.
They said it was clear she could not restore faith in Britain's biggest police force after one of her officers, Wayne Couzens, was sentenced to a whole-life term for Miss Everard's murder.
But perhaps the most egregious blunder on her charge sheet is Operation Midland, which she launched in 2014.
DAMNING DOCUMENT — AND AITKEN LINK
The astonishing stories of Witness A and Witness B's dealings with the Met are set out in a confidential police report — Document 1794 — that has been leaked to the Mail.
It was written at the conclusion of Operation Midland in 2016 by then Deputy Assistant Commissioner Steve Rodhouse, the officer in overall charge and a key ally of Dame Cressida.
His report sets out how Witness A and Witness B mimicked allegations already made by Carl Beech, aka 'Nick'.
Beech had claimed to have been the child sex victim of several Establishment figures including the late Prime Minister Sir Edward Heath, former Tory Home Secretary Lord (Leon) Brittan, former Chief of the Defence Staff Field Marshal Lord Bramall and former Tory MP Harvey Proctor.
They also molested and murdered three other boys, he claimed.
In 2019, Beech was jailed for 18 years for perverting the course of justice and paedophile offences
A senior Midland officer went so far as to declare Beech's testimony 'credible and true'.
In fact, it was total fantasy. In 2019, Beech was jailed for 18 years for perverting the course of justice and paedophile offences.
What, then, of Witness A and Witness B, who made detailed abuse and murder claims against the same group of VIPs?
In Saturday's Mail, we told how Witness A also made unfounded sexual allegations against former Tory Cabinet minister