Dean Gaffney got into a fight after trying to kiss Janice Dickinson, according to reports.
The former EastEnders actor is thought to have become engaged in an altercation with the supermodel's husband Robert Gerner during an I'm A Celebrity post-show meal.
The pair are said to have sworn and shouted at each other and also reportedly pushed one another before Dean's pal and co-star Joe Swash broke up the fight.
The alleged altercation is said to have happened following a "misunderstanding" between the two men.
The "fight" is said to have happened in front of the other I'm A Celebrity stars while they were at a restaurant in South Africa.
Speaking about the incident, Gillian McKeith said: "I saw Janice's husband Robert hold Dean's arms — he held his forearms tight, pushed him back and there was a push and pull going on.
"Then Dean released his arms and said, 'Get off me', and tried to free his arms from his grip before he swore and shouted to get away from him."
The nutritionist said Dean appeared to be "very upset" after the incident and walked over to the other side of the room.
Gillian said EastEnders actor Joe Swash had "pacified the situation".
She explained how Janice still had injuries on her face from a fall during filming, something her husband was concerned about.
Speaking to The Sun, Gillian said: "He was concerned that if someone came to kiss her it could contaminate her wounds. It was a misunderstanding."
Another witness told the publication Robert was "manhandling Dean" before the actor started "swearing and yelling".
Just days before the alleged altercation, Janice had been taken to hospital after falling and was forced to pull out of the rest of I'm A Celebrity... South Africa.
Although evictions on the show have now started, more late entries are still expected to arrive.
Joe and Dean are rumoured to be heading into the camp next week.
Robert Gerner and Dean Gaffey have been approached for comment.