Iranian state television broadcast footage on Friday of an interview with a British sailor saying he and his colleagues had illegally entering Iranian waters.
Arabic-language Al-Alam television showed an interview with the sailor in which he said "I deeply apologise for entering your waters".
"We entered Iranian waters without permission and we were arrested by coast guards. I would like to apologise to Iranian people," the official news agency IRNA quoted the sailor identified as Nathan Thomas Summers as saying.
On Wednesday, the television station had shown footage of the only woman sailor in the group also saying that they had trespassed into Iranian waters.
"Everything has been very good since we were arrested and I am satisfied," IRNA quoted Summers as saying.
"Within the past days Iranian forces have treated us nicely and very humanely. There has been no mistreatment."