Former TV Gladiator Warrior, who starred in the hit show in the 1990's, was threatened by a four-strong gang who told him they would stab him in the neck over a debt, a court was told.
A former star of the ITV show, real name Mike Ahearne, was told "I will do you in if I do not get the money" by the men in a coffee shop in Merseyside.
Now a gym owner Ahearne was targeted in the Ruben's Coffee Shop, Birkenhead, on 8 August last year by Alan Maddocks, 40, Peter Maddocks, 42, Scott Monaghan, 28 and Carl Morgan, 45.
All four were locked up at Liverpool Crown Court after pleading guilty to affray after the Crown Prosecution Service (CPS) dropped a charge of blackmail due to lack of evidence.
The court heard that Ahearne walked into the shop, on Woodchurch Road, at around 5.30pm before Morgan and Monaghan joined him, reported the Manchester Evening News.
Arthur Gibson, prosecuting, said a waitress saw the confrontation, telling the court: "Mr Ahearne told them he had no money and anyway it wasn't his debt, but Morgan insisted that the 'clock was ticking' and that 'it needs sorting'.
"(She) formed the impression that the conversation between the three men was 'heated', and on being told by the regular customer that they weren't getting their money back the two men became more aggressive."
The court was told that brothers Peter and Alan Maddocks arrived and Alan produced a Stanley knife from his pocket and said "I'll stab you in the f****** neck".
Peter then gave the 56-year-old the impression he also had a knife and told him: "I'll stab you in the other side of the neck'."
All five men then left the café and were spotted arguing by Gemma Ahearne, the former prize-winning bodybuilder's wife, who was driving past.
Monaghan was jailed for 52 weeks, Alan Maddocks and Peter Maddocks were each jailed for 56 weeks, while Morgan received a 52 week jail term.
The group were believed to have been referencing money that was loaned to one of Ahearne's friends.
In 1998 Ahearne was jailed for 15 months when he became embroiled in a plot to halt the prosecution of Philip Glennon Jnr, an associate of former international drug dealer Curtis 'Cocky' Warren.