David O'Leary: Left fuming (StuForster/Allsport)

Hammam was confronted by O'Leary after the game. The Leeds United manager was angry at the way the Cardiff chief had behaved during the game. Hammam went on a 'tour of duty' around the pitch and was behind Nigel Martyn's goal when Scott Young made the score 2-1 to the Welshmen.

Hammam said: 'He has a very good club and very good chairman but he lost his cool totally at half-time and full-time and if he wants to be a top manager he needs to control himself better.

'He very clearly stated before the game that he wanted to do as well as he can in the FA Cup and start their campaign in Cardiff and end their campaign in Cardiff. Being nice Welsh people we obliged. He deserved it. It was a natural reaction.

'He is a good manager but to change from being a good manager to being a great manager - great people have the ability to take defeat with aplomb, like their chairman. David O'Leary is a young man but he has to combine football abilities with behaviour abilities.

'But I think he will now be a much better manager -- you have to be humble. I think he has grown in stature as a manager.'

O'Leary revealed this afternoon he had spoken to Hammam by telephone today. 'Sam said he had a letter giving him authority to walk around the pitch,' he said. 'Good luck to him, but I think it's wrong. I don't think he helped the atmosphere. A football chairman shouldn't do that.'

The Football Association and their Welsh counterparts, the FAW, have launched a joint investigation into the crowd disturbances. Referee Andy D'Urso received treatment during the game after being struck by a coin, and O'Leary also complained that objects were thrown at his players.

After the game thousands of home fans spilled on to the pitch, and hundreds were seen to head towards the away supporters' section and bait the Leeds fans - only to be driven back by baton-wielding police and dogs.

Before the final whistle Hammam, who was at pitch side when Scott Young hit the 87th-minute winner, angered O'Leary by waving to the crowd.

O'Leary took issue with the former Wimbledon chief over the incident, but Hammam claims he was doing nothing out of the ordinary and that the subsequent pitch invasion was good-natured.

Hammam added: 'He is saying he is not happy with me walking in front of fans, but this is something I do every game. I am entitled to do it and I have the written permission of the Football Association. But when we went 2-1 up I did not want to offend the Leeds fans and walked round the other way.

'If you are trying to cheer the crowd what is wrong with that - as long as I am not inciting violence, which I was not? There was no crowd invasion. There was a pitch celebration after the final whistle. This is a football tradition, and long may it continue.

'They came after the game to celebrate, and we want this to continue. Some of them started taunting the Leeds fans, but taunting is part of the game as well.'

Hammam, however, stated that he is prepared to co-operate with the FA even if they insist on his club playing behind closed doors.