Putting your guest at ease before interviewing them is part and parcel of working as a radio presenter.
But host Jason Cundy's efforts backfired terribly when he chatted to a special forces veteran just minutes before the pair were due on air together, the Daily Mail reports.
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Former Special Boat Service sniper Anthony 'Ant' Middleton is alleged to have grabbed TalkSport's Cundy by the neck and thrown him against a wall after taking offence.
The 37-year-old, who stars in the TV series SAS: Who Dares Wins, has been questioned under caution by police over the incident, although no further action is being taken.
Former footballer Mr Cundy, 47, was said to have suffered whiplash during the fracas last month and left the radio studio in South London saying he was in agony. He reported the incident to police the next day and appeared wearing a neck brace.
As Mr Cundy limped away following the alleged fight, another TalkSport host, Andy Goldstein, had to step in to interview Mr Middleton about his TV show.
The Mail on Sunday understands the tussle came about after the former Chelsea player cracked a joke about the tough guy's criminal past. Mr Middleton was jailed in 2013 after assaulting two police officers during a bust-up in an Essex nightclub which was caught on CCTV.
A source said: 'Jason and Ant were sitting together in the studios waiting to conduct an interview. Everything was going fine before Jason tried to be funny. He brought up the fact that Ant spent four months behind bars for attacking police officers. Because Jason's sister is a police officer the incident is quite sensitive to him.
Ant immediately took offence and a friendly tussle turned into a real fight and Jason was thrown across the room. He was really hurt and couldn't conduct the interview.
Jason was seething about what happened so went to Twickenham police station near where he lives.
Father-of-four Mr Middleton has spoken publicly about his 'very dark moment' after being found guilty of unlawfully wounding a male PC and of common assault on a female PC in his home town of Chelmsford.
But he hid his criminal past from television producers seeking to cast ex-Special Forces troops as instructors on the Channel 4 reality show.
A Metropolitan Police spokesman said: 'A man has been interviewed under caution by detectives from Lambeth who were investigating an allegation of assault. After inquiries had been completed, no action was taken against any party.'
The Mail on Sunday was unable to contact Mr Cundy, whose ex-wife Lizzie is also a broadcaster. TalkSport confirmed they were aware of an incident, but declined to comment further.
But a spokesman for Mr Middleton said last night: 'No incident of any note took place at TalkSport. Ant was filming an online video with Andy Goldstein and Jason Cundy, followed by a live interview.'