Lord Janner, whose son attended the University College School in Hampstead, where four paedophile teachers used their positions to abuse teenage pupils

To upwardly mobile residents of Seventies North London, an old boy’s tie from University College School, Hampstead, was the ultimate social calling card.

An exclusive institution, with Edwardian architecture and picturesque games pitches, it admitted only the brightest boys, and was rightly famed for creative, sporting and academic prowess.

The ranks of ‘Old Gowers’, as alumni are known, included a host of the great and good, from athlete Roger Bannister to film star Dirk Bogarde and the celebrated mountaineer Chris Bonnington.

Despite its fee-paying status, UCS was (and still is) run according to a liberal philosophy that included a statutory ban on religious education and a refusal to acknowledge, in any formal way, differences of ethnic or cultural background.

This made it the favourite public school of the local area’s social elite, who — in time-honoured tradition — were happy to overlook any principled opposition to private education when it came to the treatment of their own children.

The roster of pupils duly contained the offspring of many Labour grandees, including both sons of the party’s former Prime Minister, Harold Wilson.

A few years later, UCS would educate the likes of Tristram Hunt, the son of a Labour peer (and now Shadow Education Secretary), Jonathan Freedland, the Left-wing commentator, and Ian Katz, a former Guardian journalist who is editor of BBC2’s Newsnight.

Yet behind its historic red-brick facade there lay a troubling secret. For throughout this heady era, the UCS staff room was home to four paedophile teachers, who used their positions of authority to prey on teenage pupils.

The ring, led by politics teacher Michael Densham, was sensationally exposed in 2004 by the writer and entrepreneur Jonathan Self, who had attended the school with his brother, Will, the novelist.

In an autobiography titled Self Abuse, Jonathan revealed that he had ‘suffered repeated sexual abuse by two of the masters at UCS senior school for most of the three years I spent there’, from 1970 onwards.

The book devoted an entire chapter to this catalogue of exploitation, saying it began on a school trip when he was ‘barely 13 years old’ and Densham plied him with alcohol until he was ‘vomiting drunk’.

‘He begged me to take off all my clothes and get into bed with him,’ Self recalled. ‘What started as, effectively, a rape continued much in the manner of an illicit affair.’

The teacher, then in his 30s, would typically take his victim to ‘restaurants, pubs and a gay club in the Finchley Road’, before ending their liaisons by forcing him to have sex in his car (‘short and hurried’) or in a bedroom of his home in Ealing, ‘a drawn-out business’ Self found ‘abhorrent’.

Over the course of the abusive relationship, Self says that Densham introduced him to several other paedophiles connected to UCS, including former pupil Basil Moss, who ‘was always kissing me and pinching my bottom’, and two teachers from the UCS junior school ‘who made a similar nuisance of themselves’.

Self was then raped by yet another professional associate of Densham’s called Tony Ford, a UCS art teacher, who ‘became so insistent I have sex with him that in the end I gave in’.

‘I wouldn’t keep harassing you,’ Self recalled Ford saying on the day he finally consented. ‘But I know you have done it with Mike and it just isn’t fair that you won’t do it with me.’

This troubling saga generated a smattering of ugly headlines when Self’s book was published, just over a decade ago.

Yet, perhaps due to the fact that Densham and Ford were no longer around (one disappeared, one committed suicide, in murky circumstances) no proper police investigation was conducted.

Instead, to the presumed relief of the authorities at UCS, the saga of the Seventies paedophile ring was allowed to slide quietly into history. That was then, however.

The ring, led by politics teacher Michael Densham, pictured, was sensationally exposed in 2004 by the writer and entrepreneur Jonathan Self, who had attended the school with his brother, Will, the novelist

Today, things could be about to change. For, more than 40 years after Self was abused, events only a few miles from leafy Hampstead are about to return this sordid chapter in the public school’s history to the top of the news agenda.

To blame is Greville Janner, the former Labour MP, who has been splashed across the front pages in recent months.

The 86-year-old peer, a flamboyant amateur magician ennobled by Tony Blair, is at the centre of heated public debate over claims that for decades he was a prolific abuser of young boys.

Director of Public Prosecutions Alison Saunders announced in April that the police had sufficient evidence to charge him with 22 paedophile offences, including 16 indecent assaults and six acts of buggery.

She added, however, that he will not face trial on a single one of the charges, involving nine separate children from 1969 to 1988, on the grounds that he is suffering dementia, which means he is ‘not fit to take part in any proceedings’.

The decision has sparked huge controversy, not least since dozens of further alleged victims have since come forward. The ruling is being reviewed, and an announcement regarding whether it will be overturned is expected imminently.

Police in Scotland are also looking into claims that Janner abused boys north of the border. Since they operate under a separate legal system to England, the peer could, in theory, face prosecution there.

The ongoing scandal further deepened this week when Labour MP Simon Danczuk used Parliamentary privilege to claim Janner had ‘violated, raped and tortured’ children inside the Houses of Parliament, molesting a nine-year-old boy, Paul Miller, at the Chapel of St Mary Undercroft in the Palace of Westminster.

Miller, who has given a signed statement to police, believes he was targeted after Janner began visiting his school, Braunstone Frith Primary, in Leicester.

He says he was then abused when the MP invited eight of its pupils to visit him at the Commons in 1969.

The Janner family — who have always proclaimed the peer’s innocence — would doubtless respond to Miller’s claims by pointing out that Janner was not elected to Parliament until 1970.

Either way, it’s nonetheless intriguing — not to say somewhat troubling — to discover that Braunstone Frith Primary wasn’t the only school on Janner’s radar during this murky period in his personal history.

During the late Sixties and Seventies, I can reveal that Janner just happened to be a regular visitor to the classrooms of University College School, where his circle of close acquaintances included a bespectacled teacher by the name of Michael Densham.

An exclusive institution, with Edwardian architecture and picturesque games pitches, University College School admitted only the brightest boys, and was rightly famed for creative, sporting and academic prowess

The two men met in 1968, when the future MP for Leicester West, who lived in Hampstead, decided to send his son, Daniel, to UCS.

They proceeded to forge a friendship which, according to several former pupils and members of staff, saw Janner build close links with Densham and his teenage pupils, visiting the school to lecture them on a regular basis.

Intriguingly, in light of this week’s revelations, he also invited its pupils on guided tours of Parliament.

What is more, during three General Election campaigns, one in 1970 and two in 1974, the paedophile teacher would even drive bus-loads of UCS sixth-form boys to Leicester to spend day after day working in Janner’s campaign office, and canvassing on his behalf.

‘Denham and Janner were as thick as thieves,’ is how one former pupil puts it.

‘He was constantly coming into school to do things such as lecture Mike’s politics society or help out his A-level class with projects.

‘You don’t think much of it at the time, but Densham was a showy bastard, who was well known for groping pupils and making dodgy sexual remarks.

‘With the benefit of hindsight, it does all look very, very suspicious.’

Paul Manski, a lawyer who left UCS in 1973, says: ‘Greville Janner came to school quite regularly to speak. I can recall two or three lectures while I was in the sixth form. They took place in a downstairs theatre called the Crypt, next to the cricket nets.

‘There were also quite a lot of times when Densham organised visits by boys to his constituency during elections.’

A friend of Manski, who went on one such Leicester trip, says: ‘It was sold to us as a chance to see a typical day in the life of a constituency MP.

‘I remember being shown around the offices of a local newspaper, going to his surgery and doing some canvassing, which was odd as I wasn’t really a Labour supporter. Greville Janner was perfectly friendly, and he and Densham were clearly close.

‘Densham was drawn to famous people and was an inveterate name-dropper. He always used to claim to be on first-name terms with Harold Wilson, too.’

Michael Alsford, a teacher at UCS from 1967 until 2005, confirms that Densham and Janner were well acquainted. He describes his former colleague as a ‘brilliant teacher, but obviously a flawed man’, and says that Densham would ‘take groups of boys up to Leicester West to help with canvassing at election times’.

Densham was drawn to famous people and was a inveterate name-dropper. He used to claim to be on first-name terms with Harold Wilson, too

‘We had plenty of elections in the Seventies, and I clearly remember Mike talking about it.’

Another former student recalls joining Janner on a private tour of the Commons.

‘I was a few years below his son, Danny, and met the MP when he came to speak to Densham’s class. We had a chat, and he then sent me a letter asking me to visit, so I did. Lots of other pupils went on similar tours.

‘Obviously, we all thought at the time that he was just being kind. But given what we now know, the whole thing does seem very dubious.’

All of which poses a couple of pressing questions. First, did Janner pursue relationships with any of the many, many boys he met via University College School?

And second, was he a member of a wider paedophile ring whose members included Mike Densham, Tony Ford and a smattering of UCS colleagues?

Perhaps they would be best pursued by the police.

In a statement this week, a UCS spokesman said it ‘takes the welfare and protection of its pupils as a matter of the utmost importance, and if the police were to contact the school we shall give them every assistance’.

One person who won’t be able to help them, however, is Michael Densham. Forced out of UCS in July 1980, after several complaints about his conduct, he was subsequently sacked by a primary school in Ealing, West London, after being caught sexually abusing a paperboy.

At around the same time, he inherited hundreds of thousands of pounds on the death of his well-to-do parents, but spent it all, in the words of a friend, on ‘boys, holidays and nightclubs’ in little more than a year.

Finding himself destitute, he began stealing money from former friends, was jailed in the late Eighties for credit card fraud and eventually committed suicide by jumping in front of a train on February 11, 1998.

As for Ford, the second named member of the UCS paedophile ring, he was suspended one Thursday in 1978, amid allegations that he had groped a teenage pupil.

He walked back to his nearby flat, packed a suitcase and drove away, never to be seen again by friends, colleagues or family members.

‘Tony just disappeared,’ says Alsford. ‘Police refused to investigate, so his mother hired a private investigator. But they never found any trace of him.’