The body of Jonathan Adair Jr. was found at property in Troon, Ayrshire on Saturday just days after being freed from prison.
“Mad Pup” had only recently returned home from Kilmarnock prison where he had been serving time for driving offences.
Cops are currently treating the death as unexplained and a force spokesman said a post-mortem will be carried out and a report is to be sent to the procurator fiscal.
The dad-of-two was due to face drugs charges in the New Year and has been in and out of prison for the last few years.
Adair senior is one of the most fearsome members of the Ulster Defence Association to emerge from Belfast and spent 16 years inside only to be freed under the Good Friday agreement.
The family settled in Scotland after “Mad Dog” was forced to flee Northern Ireland over a decade ago.
Shocked friends and family have taken to social media to pay tribute to Mad Pup,
Jim Holmes wrote: “Gutted to hear da sad loss of my cousin Jonathan adair will b missed truly.”
Angela Robertson said: “Jonathan Adair you where the funniest guy iv ever met such sad news another young life took just like that R.I.P big man.”
Natalia Gracey wrote: “R.I.P Jonathan Adair , thinking of the laughs we used to have chum, my heart breaks for your family and kids.”
Stewart Beck Grew said: “Grew up with him so sad for his family.”
Stacey Slaven added: “R.I.P big yin.”
Adair Jr was a known drug user and has previously been jailed for a drug fuelled rampage at an actresses home after she refused to sell him cannabis.
In 2013 he was held on remand for trying to headbutt a man and extortion and was finally jailed in December last year for violating a driving ban.
Police Scotland confirmed the death in Troon on Saturday.
A spokeswoman said: “At around 5.15pm on Saturday police received a report of a body of a man having been found within a property in Templehill in Troon.
“A postmortem will be carried out in due course to establish the exact cause of death.
“Officers are treating it as unexplained at this time.”
Johnny Adair and pal Sam McCrory survived a murder plot in 2013 which was foiled by MI5.