Moment cannabis kingpin Mr Nice was told phone was being tapped

Howard Marks's smuggling of cannabis across the world made him millions of pounds and gave him the luxury lifestyle that most of us can only dream of.

The self-styled Mr Nice was the drugs kingpin who evaded police on multiple continents for decades. 

But the moment the Welshman discovered the authorities were closing in on him is revealed in a new documentary.

Hunting Mr Nice: The Cannabis Kingpin plays to viewers a recording of a phone conversation where an associate told the smuggler in Cockney rhyming slang that his phone was being tapped by the US drug enforcement agency.

The man told Marks, 'I think your dog is sick', prompting the drug lord to ask if it was 'seriously ill'. 

Craig Lovato, the DEA agent who eventually snared Marks, admits he was confused by the message until a fellow expert told him: 'The dog means phone. In Cockney, it's dog, bone, phone. So when someone says your dog is sick, it means your phone is tapped.'

The revelation that his calls were being listened to prompted Marks to hold up his phone to what Mr Lovato calls his 'fantastic' stereo set, 'so I could listen to some classical music that he was listening to'. 

Marks, who died from cancer in 2016, was finally arrested in 1988 and went on to spend seven years behind bars at a prison dubbed 'America's toughest'.

After his release, his bestselling autobiography, Mr Nice, won him millions of fans around the world and sparked a second career as a public speaker and campaigner.

The new documentary brings together Marks's criminal inner circle and those who hunted him.

It traces activities in the mid-1980s, when he was trafficking tens of millions of dollars worth of cannabis across the world.  

As well as DEA agents, detectives from the Metropolitan Police and officials from HM Revenue & Customs were on his tail.

Marks was born in Kenfig Hill, near Bridgend, South Wales, in August 1945. His father was a foreman at the Port Talbot steelworks, whilst his mother was a teacher.

While many of his contemporaries went to work in the steel industry or as miners, Marks won a place at Oxford's Balliol College to read physics.

It was there that he began smoking cannabis, which was widely available to undergraduates. 

He endured the harrowing experience of a close university friend dying from taking a combination of drink and drugs, but that did not stop Marks from using illicit substances.

After graduating from Oxford in 1967, he moved to Brighton with his first wife Ilze and initially embarked on a post-graduate science course at Sussex University. 

But he gave that up after realising that smuggling cannabis could make him a lot of money.

As he revealed in his book, Marks first used the drum kits and speakers of travelling rock bands to hide drugs. 

He then moved on to deliveries of furniture, allowing him to expand his operation.

However, in 1973 he was arrested in the Netherlands on drug-trafficking charges.

Marks had by then been asked by a Balliol contemporary who was in MI6 if he would consider using his underworld knowledge to help British intelligence.

This was the story the smuggler told to police in Holland in the hope of persuading them he was not a genuine drug dealer.

But the Dutch police did not believe him and instead extradited him to Britain.

Marks was released on a £20,000 bail, which he then jumped. The criminal went on to use a host of aliases, disguises and false passports to come and go.

Yet, in 1979, the smuggler was arrested again at a Channel port. 

In his trial at the Old Bailey in 1980, Marks - who was charged with being the British link in a £20million cannabis operation - again claimed he had been working for MI6.

He had the backing of a Mexican witness who gave evidence saying that Marks was working for Britain and Mexico to infiltrate the Colombian drugs cartel and the IRA.

Amazingly, the jury believed the far-fetched tail and Marks was acquitted. 

He did, though, get a sentence of 18 months for possessing false passports, but was released after two months because of the time already spent behind bars. 

Once back to business, Marks expanded further - to the point where he had 25 companies that laundered his drug money. 

By then, he was living with second wife Judy and their children in Palma, Majorca.

But, in America, DEA agent Lovato was catching up with him. When Marks and Judy were arrested in July 1988, police seized 16 tons of cannabis worth £35million. 

Marks fought a furious legal battle to try to stop his extradition to America, but the action failed. 

At his trial, Marks was sentenced to 25 years in prison. His wife was given 18 months. 

He served less than a third of his sentence at Terre Haute federal penitentiary in Indiana before being released on parole. 

Marks was then given a £100,000 advance to write his autobiography, which was published in 1996. 

He painted himself as a good-natured drug dealer who abhorred violence.

The book was turned into a 2010 film starring Rhys Ifans. Marks stood unsuccessfully for Parliament in 1997 on the single issue of cannabis legalisation.

He and his wife separated in 2003 and the former smuggler moved back to Wales. 

Marks always cast doubt on medical evidence that cannabis has a damaging effect on the human brain, or that it could lead users to take heroin and other hard drugs. 

And until the end of his life, he continued insisting that he had committed a 'victimless crime'.

But in a 2009 interview, Judy sharply disagreed with her former husband, telling the Mail: 'For years I was terrified living with him. I used to beg him to stop dealing. 

'I nagged him non-stop. We quarrelled over it. But he was unbelievably selfish. And the family was devastated, destroyed. 

'I look back and think what an idiot I was. I regret that I wasn't more forceful.

'His own children got hurt. Patrick was only one when both of us were arrested. I was in prison for a year in Madrid away from the children. 

'It was a terrible, painful time and Patrick suffered the most. A lot of people got very hurt. So no, I wouldn't call his crimes victimless.' 

The two-part documentary Hunting Mr Nice: The Cannabis Kingpin, airs tonight on BBC Two at 9pm, and next Thursday.