The blood-soaked body of a private detective who probed the disappearance of Maddie McCann has been found at his home in Surrey.

Mystery surrounds the death of Kevin Halligen, 56, who is said to have presented himself as a 'cloak-and-dagger, James Bond-style spy'. Police today confirmed to MailOnline today that a probe has been launched into the circumstances.

Halligen took over the private investigation into the McCann case in March 2008 but was later accused of conning the family fund out of £300,000.

It is believed he was found at the home he shared with his long-term girlfriend. There is no suggestion that she was involved in his death. Sources said the house was 'covered in blood'.

Kevin Halligen, 56, pictured, was found dead at his Surrey home. Police have launched an investigation into the death which is being treated as 'unexplained', a spokesman said

A spokesman for Surrey Police said today: 'We were called to an address in Cobbett Hill Road, Normandy, Guildford, on Monday following a report of a man in his 50s having been taken unwell, who subsequently died.'

His death is being treated as unexplained but a source who knew the Dublin-born debt-ridden private eye say he was 'a boozer' and 'drink was inevitably his downfall.'

Former associates of Halligen described him as a heavy drinker. One ex-colleague told MailOnline: 'The house was covered in blood but apparently that was from Kevin falling down so much.

'His body is now in the morgue. The police are looking into it.'

Defence consultant Tim Craig-Harvey, a former associate of Halligen, wrote online: 'The lies and alcohol finally caught up with him.'

Another source told MailOnline: 'He died at his girlfriend's place near Guildford, a miserable pathetic death caused by alcohol.'

The McCanns hired Halligen's firm in a bid to boost the search for Maddie after failing to come up with any plausible leads one year after she went missing.

They agreed a £500,000 fee with Oakley International, which was described by a source close to the family as 'extremely secretive' but 'absolutely the best'.

Halligen took over the private investigation into the McCann case in March 2008 but was later accused of conning the family fund out of £300,000

Defence consultant Tim Craig-Harvey, a former associate of Halligen, wrote online: 'The lies and alcohol finally caught up with him'

Kate and Gerry McCann were initially impressed by Dublin-born Halligen, believing he 'was in a different league' to other private investigators.

He boasted of employing ex-FBI, CIA and Special forces officers while offering undercover surveillance and intelligence gathering in Portugal.

The detective even said he could provide satellite imagery and details of telephone traffic from the night Madeleine disappeared.

But within a year, questions began to emerge about Oakley and Halligen in particular.

Researchers claimed that the firm had not looked into hundreds of calls made to a special hotline - while specialists found that their bills were unpaid.

The promised satellite images also allegedly turned out to have been grabbed from Google Earth.

Kate and Gerry McCann were initially impressed by Dublin-born Halligen, believing he 'was in a different league' to other private investigators

Six months into the highly-paid assignment, the McCanns were growing increasingly concerned about Halligen.

A family friend said: 'He had this sense of cloak-and-dagger, acting as if he were a James Bond-style spy.

'The McCanns found him hard to deal with, because he was forever in another country and using different phones. He promised the earth but it came to nothing.'

The contract was terminated early after £300,000 had been paid to Halligen.

Kate recalled: “Oakley’s proposal and overall strategy were streets ahead of all the others we’d considered and the company came highly recommended.”

Initially Kate and heart doctor Gerry, 49, from Rothley, Leicestershire, were impressed with Halligen’s work with Kate writing: 'There is little doubt that progress was being made.'

The McCanns hired Halligen's firm in a bid to boost the search for Maddie (pictured) after failing to come up with any plausible leads one year after she went missing

But the couple later started to have grave concerns and decided to sack him in September 2008 terminating his £500,000 contract.

Kate recalled: 'It was quite acrimonious and unfortunately that was not the end of it.'

Several months later investigators sub contracted by Halligen cane forward demanding payment for his services which they hadn’t received.

Kate said: 'We were upset that, although a lot of hard work had been done on Madeleine’s behalf, it seemed money provided by her fund might not ever have reached the people who had earned it.'

MailOnline understands that relations broke down after the detective's team discovered he was enjoying a lavish lifestyle, staying in the best hotels and eating at the top restaurants in London - all at the expense of the Find Madeleine fund.

Former doctor Kate, 49, now a medical worker previously told how the family had suffered 'a particularly bad experience' with Halligen, who she knew as Richard. She described the ordeal he put them through in her best seller 2011 book 'Madeleine'.

Colleagues said that far from being an expert in undercover operations, Halligen was 'out of his depth' with 'no experience of such investigations.'

There is no suggestion that any former associates are involved in the death of Kevin Halligen.

After being sacked from the McCann investigation in 2009, Halligen was arrested in the UK and extradited to America on fraud charges for an unrelated case

He pleaded guilty to defrauding Trafigura, based in the Netherlands, who had hired him to help free two company executives arrested in Ivory Coast in 2006.

He received about $12 million to provide 'security, intelligence and public relations'.

Trafigura gave Halligen an additional $2.1 million to 'hire lobbyists and influence officials in the United States on Trafigura's behalf'.

The next day, Halligen used nearly $1.7 million of that money to buy a large home with a swimming pool.

The Washington Post reported at the time: 'Owners of Washington restaurants remember him spending thousands on long, boozy days and evenings. He traveled everywhere in a chauffeured Lincoln.'

One restaurant owner said he and his staff called Halligen 'James Bond' because of his stories of spy derring-do and his habit of tossing around huge sums of cash.

It is believed he was found at the home of his long-term girlfriend, which is among the private Henley Park gated community (pictured) in Guildford

His fraud conviction carried a maximum of 20 years in prison, but under federal sentencing guidelines he would serve no more than 41 months.

As he had been in custody awaiting trial for 42 months, he was freed and deported, returning to his birthplace of Dublin.

In 2014, Kevin Halligen made a rare public appearance, agreeing to be interviewed for a Channel 5 documentary - The McCanns and The Conman.

He denied that he misused money raised to find Madeleine. Answering claims that he spent the money on first class travel, luxury hotel suites and a chauffeur, he said: 'It is gross distortion of what was actually happening.'

A source close to Kate and Gerry McCann said they had terminated their contract with Oakley international in September 2008 and had not had anything to do with Kevin Halligen since.

'Clearly this is now a matter for the police and the Coroner's office,' the insider said.

A close pal of Maddie’s parents said: 'The man was a fantasist. He promised lots of things that never happened.

'He even claimed McCann spoke Clarence Mitchell was working for MI5!'

'Kate and Gerry and Madeleine’s great uncle Brian Kennedy, who had brought him on board, were bitterny disappointed with him towards the end of his contract.

'They didn’t need the extra grief, they already had enough. '

In the end they took issue and had to withhold his final payment. He just ran away from his debts around the world.”

The hunt for Madeleine McCann continues, more than 10-and-a-half years after her disappearance.

A team from Scotland Yard has been probing the case since 2011 at a cost to the British taxpayer of more than £11.3million. Portuguese police have lead status in the investigation.

In October 2017, the Home Office allocated an extra £154,000 to Scotland Yard to pursue a 'critical line of inquiry' and extend the search to the end of March 2018.

Clarence Mitchell, spokesman for Kate and Gerry McCann said today: 'They had no further association with Kevin Halligen after the termination of his Oakley International contract nine years ago and under these circumstances they will not be commenting now. Clearly this is a matter for the police and coroner’s office.