Jeremy Corbyn was left visibly frustrated after being quizzed about his involvement in an event which included the honouring of a Palestinian suspected of involvement in the Munich Olympics massacre.
He had earlier stated he had been at a wreath laying ceremony in 2014 "but didn't think he had been involved."
Questioned again about the matter on Tuesday he said: "I laid one wreath along with many other people, as I've said, of all those who died in the awful attack in 1985."
The Labour leader sighed and rolled his eyes when asked if he specifically laid a wreath at the event.
Telling the journalist "you seem not to understand", Mr Corbyn maintained the party line, which stated he had attended the event to remember victims of a 1985 Israeli air strike on Palestinian Liberation Organisation (PLO) offices in Tunis.
The controversy arose after the Daily Mail published pictures showing Mr Corbyn holding a wreath in the cemetery, which it said were taken in front of a plaque honouring the founder of Black September, the Palestinian terrorist group thought to be responsible for the Munich Olympics massacre.
Labour initially maintained that Mr Corbyn was paying his respects to the victims of a 1985 Israeli airstrike on Palestinian Liberation Organisation offices in Tunis.