Almost a quarter of a century may have passed, but the bizarre and outwardly tawdry nature of Stephen Milligan’s death has lost little of its ability to shock.

The 45-year-old MP, a rising star of John Major’s Conservative party, was found lying on a kitchen table in his terraced home near the River Thames in Chiswick on the afternoon of Monday, February 7, 1994.

His body was naked, save for a pair of women’s stockings and suspenders, plus a black bin-liner over his head. Around his neck was a length of electrical flex, which had apparently been used to strangle him.

His mouth meanwhile contained a single segment of orange.

Stephen Milligan was found dead lying on a kitchen table in his terraced wearing just a pair of women's stockings and suspenders

A post-mortem examination soon found that Milligan had died of suffocation caused by pressure from the ligature around his neck, most likely in the early hours of Sunday morning.

In the ensuing media circus, detectives quickly took the view that the MP, a bachelor, had suffered a fatal accident while carrying out a solo sex act.

Specifically, they believed he’d been indulging in ‘auto-erotic asphyxiation’ — the highly-unconventional practice of seeking to increase sexual excitement by restricting the supply of blood to the brain.

A hastily-convened inquest, which opened the following week, reached a similar conclusion: West London Coroner, Dr John Burton, found no evidence to suggest that the Eastleigh MP had been murdered or committed suicide, instead recording an official verdict of ‘death by misadventure’.

To devastated friends and colleagues, the whole thing quite understandably came as a terrible bolt from the blue.

A post-mortem examination soon found that Milligan had died of suffocation caused by pressure from the ligature around his neck (pictured police move furniture from Milligan's London home where he was found dead)

Many found it impossible to square the gregarious and charming Stephen Milligan they knew — a churchgoing former journalist, with a keen intellect, unremarkable love-life (an ex-girlfriend was the future Tory MP Julie Kirkbride), and infectious sense of humour —with the sad and somewhat lonely circumstances of his demise.

Yet in the febrile world of Westminster, where the charismatic former Oxford Union President had been tipped as a future Minister, even the most grotesque personal tragedies tend to be quickly politicised.

Just a few months earlier, John Major attempted to shore-up his failing government by launching a so-called ‘Back To Basics’ campaign, in which he pledged to place traditional family values at the heart of his future administration.

Unfortunately, for the former Prime Minister, several prominent Tory MPs had at this very time been conducting extra-marital affairs.

They ranged from Steven Norris, who’d separated from his wife and clocked up no fewer than five mistresses, to Tim Yeo, a stern critic of single mothers who’d nonetheless fathered two secret love children during extra-marital affairs, to Hartley Booth, a married father-of-three and sometime Methodist preacher who admitted ‘kissing and cuddling’ his 22-year-old researcher.

In the wake of these — and several other — scandals, Milligan’s death struck a raw public nerve, helping cement the reputation of Major’s party as one of sleaze, hypocrisy and sexual peccadillo.

BBC newsman John Simpson now suggests that Milligan was a victim of foul play

Not only did it contribute to a thumping defeat for the Tories in his former Eastleigh seat at the ensuing by-election, but also to their landslide ejection from office in the 1997 General Election.

To this day, Stephen Milligan’s death is associated with the sleaze and indiscretion of our ruling class.

But what if something else actually lay behind this most notorious of Parliamentary tragedies? What if Stephen Milligan didn’t die by his own hand, but was instead the victim of foul play? What if the unbecoming circumstances in which his body were found had nothing to do with a bizarre sexual experiment, but were actually part of a sinister cover-up?

Just such a sensational theory was this week floated by veteran BBC newsman, John Simpson.

Simpson is a friend and former colleague of Milligan (who’d worked at the Economist, Sunday Times, and BBC before entering politics). He told an audience at the Henley Literary Festival that he believes the MP was murdered by Russian spies.

The motive? Revenge for the fact that Milligan had reported on corruption and organised crime in the country during his career as a journalist.

‘Stephen was a real good friend of mine,’ he said. ‘When I read in the newspaper that he had died in this macabre fashion in this awful sex experiment with a bag over his head, I just couldn’t believe it, there was nothing in it that seemed to do with Stephen.’

Simpson added that, although Milligan had ‘uncovered a lot of dodgy things’ in Russia during his journalistic career, he’d given little thought to any possible murder conspiracy until several years later, when he was discussing the MP’s death with a mutual friend.

‘He said ‘I’m thinking of writing a book about it because it was so obvious that he was murdered by the KGB. What better way to kill somebody without there being any form of investigation than this?’ Simpson recalled.

‘Many people just thought it was funny or savage or were too embarrassed to have anything to do with it. Then [the mutual friend] came up with the fact that at least two people, critics of the Yeltsin government, had died in the same way in Russia.’

So taken was Simpson by the theory (lent further weight by the more recent Skripal affair) that he’s now used it as the inspiration for a novel, Moscow, Midnight.

It opens with the death of a government minister who is uncovered in a similar state to the MP. ‘In a way, [the book] was a kind of homage to Stephen who was a lovely intelligent and sensitive man, who died in such terrible circumstances that it marred the whole of his life,’ he added.

Simpson has yet to elaborate on his remarks, so it’s impossible to be sure if any wider evidence underpins his theory.

Neither has he so far identified the other ‘critics of the Yeltsin government’ who met a similar fate to Milligan. And even if he did, that wouldn’t necessarily prove that Milligan was murdered.

However, you don’t have to spend long exploring the circumstances of this most notorious of political scandals to find informed sources who smell a rat about his death. Take, for example, a ‘former girlfriend’ who was interviewed by the Independent newspaper on February 9, 1994, just two days after his body was found.

The woman, who asked not to be named, said she believed he’d been killed by someone seeking to destabilise the Major government — which could include either Russian spies or opponents of the then-recent Anglo-Irish declaration, aimed at bringing peace to Northern Ireland.

In her interview, the girlfriend argued that the kitchen of his home at Black Lion Lane in Chiswick was an unlikely location for him to indulge in a sex act. ‘I believe he was murdered,’ she said. ‘Even if you accept that he was up to these practices — and I know him well and he wasn’t — then why would he do it where he was found?

‘He was in the kitchen which is draughty, which has tiled floors and which is not particularly secretive; there are French windows that people can see through.

‘On the other hand, that is the perfect place to leave a body where you know it will be seen. And the day he was found was the day of the Conservative Winter Ball, a time when his death would cause maximum embarrassment.’

Take also Gerald James, a businessman who achieved prominence during the early Nineties when his company, the arms firm Astra, was caught up in the so-called ‘Arms to Iraq’ affair. Astra collapsed after being accused of using a subsidiary to break an embargo to sell weapons that ended-up in the hands of Saddam Hussein.

Soon afterwards, James turned whistle-blower, insisting it was one of several companies whose activities had been quietly sanctioned by the British government.

The 1996 Scott Report vindicated many of his claims. Several years later, James published a memoir of the affair, titled In The Public Interest.

Though little noticed at the time, the book makes intriguing reading in light of this week’s remarks by John Simpson, for it suggests that Milligan was one of up to eight individuals killed in remarkably similar circumstances by the British security services to keep details of government involvement in illegal arms sales from becoming public.

That may seem too fantastical to believe.

But only this week a tribunal heard how MI5 agents have been given authorisation to commit ‘murder, torture and sexual assault’ on British soil without fear of prosecution in order to protect national security. Not only that, this licence to commit ‘grave criminality’ has been granted for the past 30 years.

Among the suspicious deaths mentioned in Gerald James’s memoir, was that of James Rusbridger, a 65-year-old former MI6 officer turned journalist who died just nine days after Milligan.

Rusbridger was found lying on his stomach on the landing of his rented home in Devon, wearing a gas mask, green overalls, thick rubber gloves and a long oilskin coat. A rope, which stretched into the attic, was tied around his neck and ankles. He was surrounded by pictures of men and women in bondage situations.

Intriguingly, just a few days earlier, he’d written to a local TV station saying that he intended to investigate Milligan’s demise. A coroner nonetheless concluded that he’d taken his own life.

Also among the eight mysterious deaths cited by James was that of Jonathan Moyle, a journalist who had travelled to Chile in 1990 to dig into the sale of 50 helicopters which were to be sold to Iraq after being fitted with British made anti-tank missile guidance systems.

Moyle never completed his investigation, but was instead found crammed into a hotel wardrobe, hanging by his shirt from a clothes rail. His head was covered with a pillowcase, and over two pairs of underpants he was wearing a towel and a polythene bag.

Initially, sources at the British embassy briefed that he’d died when a sex game went wrong. It wasn’t until eight years after his death that an inquest concluded that Moyle had been ‘unlawfully killed’ by a ‘person or persons unknown’. Speaking in September 2010, his former fiancée said: ‘The British intelligence services tried to smear Jonathan suggesting he was sexually deviant.’

In his aforementioned Nineties memoir, businessman Gerald James explained that staging deaths via auto-erotic asphyxiation was a favourite technique of secret agents.

The reason — he argued — was that the deeply unedifying circumstances of such deaths make them unlikely to be properly investigated. After all, friends and family of the deceased are usually too embarrassed to want them to garner much attention.

Twenty years on, that remains his view. Indeed, speaking to the Mail this week, the former businessman, who nowadays lives in Barnes, South-West London said he still believes Milligan was murdered. The particular motive, James explained, was to prevent him from revealing details of the Arms to Iraq affair.

‘At the time of his death, Milligan was Parliamentary Private Secretary to Jonathan Aitken, the defence procurement minister, so he would have had access to sensitive documents. If he uncovered evidence of a cover up, and was prepared to turn whistle-blower, then I believe the chances of him being killed by the intelligence services were very high.’ James added that Milligan was observed shortly before his death having a furious row with one of his party whips.

‘Milligan would have known all about dirty tricks and covert arms deals. Presumably he argued with the whip because he had questioned policy and threatened to spill beans.’

Perhaps intriguingly, given this claim, the immediate aftermath of Milligan’s death saw his Commons office cleared of papers by MI5, according to contemporary newspaper reports.

What’s more, a report in the Sunday Express six days after the 1994 tragedy suggested that a ‘mystery man’ was in his Chiswick home before police arrived on the scene on the day his body was found.

The article suggested that the man in question was from the MoD and had been sent ‘to check whether any confidential or sensitive papers had been left lying around’ and presumably remove them. However the MoD denied any such official had been sent, insisting there was no ‘security aspect’ to the case.

Still more bizarrely, reporters at the scene said that on the evening of Milligan’s discovery, detectives carted off several bags of documents, plus two kitchen cupboard doors ‘which had been removed at the hinges’ and the top of a ‘modern round pine table’.

Of course, none of these strange episodes proves that Milligan was murdered. But they do provide grist to the mill of the con- spiracy theorists.

Yet another important detail regarding his notorious death is that no alcohol or drugs were found in his blood — a somewhat unusual fact given the supposed nature of his death.

It was partly this fact that in the Nineties, persuaded one of Milligan’s closest friends, the journalist and broadcaster Andrew Neil (who was at the time editing the Sunday Times) to instruct a team of his reporters to investigate the death.

‘[Stephen] was a brilliant journalist and wonderful company, with a zest for life, food and ideas and an infectious cackle,’ Neil recalled this week. ‘I was devastated by his loss. He was such an engaging and straightforward character that I was immediately suspicious.

‘I knew several of his former girlfriends well enough to ask privately if there was anything in his sexual behaviour to suggest the sort of activity that led to his death. They were adamant — no, all perfectly normal.’

Neil adds, however, that his reporters were unable to come up with concrete evidence of wrongdoing.

‘In the end we were grasping at straws. Investigative journalism is at its weakest when you’re trying to prove something you desperately want to be true, so in the absence of firm evidence I called the team off, with some sadness.’

Much like James and (more recently) John Simpson, Neil nonetheless occasionally wonders if we have ever been told the full story about the death of Stephen Milligan.

But the sad fact is that the one person who really knows how the tragic Tory MP met his end is no longer around to tell the tale.

Unless of course he’s not the only one who knows the truth.