Wenger has been critical of clubs and managers who have made so-called 'illegal' approaches to his players and was unequivocal in his condemnation of Ferguson for speaking to Vieira's agent Marc Roger about the France midfielder in the summer.

But on the eve of the new Premiership season, Wenger revealed that he does not wish to see United punished by the FA and admitted that he has used a similar practice in the past. Asked if he had ever made an approach to a player or agent, the Arsenal manager said: 'The agent.You can always ask an agent if his player is for sale or not.

'Of course, I have done that. The agent can say he's got four years left on his contract and that he's happy. If that is the case then I stop it.'

Wenger denied such a practice was tantamount to 'tapping' a player but it constitutes the same process Ferguson is supposed to have applied with Vieira. The Frenchman did not speak directly with the United manager, but has admitted conversations took place between Roger and the Premiership champions.

'I have not reported United as we have to be positive about the season,' added Wenger. 'It would not be positive to go into a dispute. I know how the transfer system works. I am not stupid enough to believe people don't speak to players.

'I don't want United reported. It's not about getting United punished. The fact that it all goes through agents means that you can never prove anything anyway.

'I think everybody does it. But we don't want to be the police. It is not up to us to report things. I don't want to be someone who rules what is right and what is wrong. It's down to the FA.'

Wenger's admission comes at a time when anarchy threatens to envelope the transfer market.

Fresh on the heels of the Vieira saga has come confirmation from United's Dutch defender Jaap Stam this week that Ferguson spoke to him in person when he was still under contract to PSV Eindhoven.

Wenger's admission could land him in trouble with the Premier League. Its rules indicate that clubs should not make 'direct or indirect' contact with contracted players and a spokesman said: 'The spirit of this regulation refers to contact with agents as well as directly with players.'