Scotland’s most notorious crime family has met a grim end as ‘The Godfather’ Arthur Thomson’s son is found dead in Glasgow.

Billy Thompson, 50, reportedly died on March 4 following a lengthy battle with heroin addiction.

He is the third of four Thompson children to meet a fateful end; sister Margaret died from a drug overdose in 1989, while brother Arthur Jr. - a.k.a. ‘Fatboy’ - was shot to death outside the family home, nicknamed ‘The Ponderosa’, in 1991.

Paul Ferris - gangland enforcer turned author - was charged with Arthur’s murder at the time, but was found not guilty after being put on trial which lasted 54 days at a cost of £4 million, at the time, the longest and most expensive trial in Scottish legal history.

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A source close to Billy told The Scottish Sun heroin played a central role in Billy’s life, and that it was something he was “known for.”

The source added: “He had a tough time because of his dad’s name and the fact he couldn’t live up to it.

“But Billy was tougher than he got credit for. He knew he was seen as the weak link and always fought back, he had guts.”

Another source told the paper the Godfather’s sons “never had what it took,” failing to live up to the reputation of their feared father.

Thompson Sr. became known as ‘The Godfather’ after making his mark as the nation’s most notorious gangster in the 1950s after which he went on to take charge of organised crime for more than three decades.

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He started out in life as a money lender, but the family quickly fell into the drug trade in the 1980s.

By the 1990s, Thompson Sr. reportedly raked in a staggering £100,000 per week as a loan shark and ruled the streets of Glasgow and its surrounding areas with an iron fist.

He was was said to crucify those who did not repay their debts, by nailing them to floors or doors, according to the number one bestselling book ‘The Last Godfather: The Life and Crimes of Arthur Thompson’ by Scottish journalist Reg McKay.

The patriarch just managed to escape death in 1966 after a bomb exploded under his car, an incident in which his mother-in-law lost her life.

Thompson Sr. eventually succumbed to a heart attack in 1993 at the age of 61.

He is now survived by Tracey, 51, his last remaining child.