FA want evidence

The FA have requested evidence after claims that Man Utd appointed two agents to negotiate Kleberson's £6m (€8.7m) transfer from Atletico Paranaense, forcing a third agent out of the deal.

Atletico Paranaense president Mario Celso Petraglia has claimed that former United chief executive Peter Kenyon told him to negotiate with two agents selected by the English champions.

Yet the News of the World claim to have seen documents which state Kleberson granted Brazilian Juan Figer sole authority to conduct the deal.

Figer said: "United cannot be allowed to behave like this.

"I am prepared to go to court, to go to Fifa, in fact to do whatever it takes to get justice."

FA spokesman Adrian Bevington told the News of the World: "Can you please pass any (evidence) you have on to us? We will consider what is appropriate from there.

"We will consider any evidence you have and forward it on to the appropriate parties if necessary."

Brazilian international midfielder Kleberson, 24, joined United in August.

Petraglia said of the transfer: "I am very disturbed. Peter Kenyon called me and said he wanted to buy Kleberson.

"He told me I should negotiate with two agents selected by Manchester United. One of them was Jorge Gama, I can't remember the other but his name is definitely in the document at the club."

Ian Hetherington confirmed he was the other agent. "We were appointed by United, yes, to represent them," he said.

United director of communications Paddy Harverson said the club would happily co-operate with any investigation.

He said: "At no point whatsoever did we insist the deal be done through two agents. It is absolutely not correct.

"We would be happy to co-operate with any investigation by Fifa if there is one.

"Like all our deals, the documentation goes through the FA, so it is all there for anyone to see."

The FA have already confirmed they are investigating American goalkeeper Tim Howard's £2.3m

(€3.3m) summer move to United.