Arsene Wenger maintains Arsenal will co-operate fully with the Football Association following allegations Cesc Fabregas spat at Hull assistant manager Brian Horton.

But the Arsenal boss stands by his captain's staunch denial.

Hull boss Phil Brown claims he witnessed Fabregas spit towards Horton as they went down the tunnel at the Emirates Stadium on Tuesday night, when Arsenal had won the FA Cup quarter-final clash via a disputed late goal from William Gallas.

The FA have written to Hull asking for their version of events as nothing was mentioned in the report of referee Mike Riley or other match officials.

Horton has contacted the League Managers' Association for their advice and is understood to be considering lodging a formal complaint.

However, until any such official notification is received, the FA cannot take the matter any further.

Wenger maintains Arsenal fully stand behind their captain, who is close to a playing return following a serious knee injury.

He said: "Cesc denies categorically what has been asserted by Hull.

"We are open to any investigation from the FA. If they want to take the matter further we will co-operate fully like we always do and for me that is the end of the matter."

Brown continued his ferocious criticism of Fabregas in interviews the following day, questioning what the Gunners skipper was doing coming onto the pitch to celebrate at the final whistle, as well as what he was wearing.

However, Wenger added: "That is unfair criticism.

"I believe that we have all the players behind the bench and I think it's completely normal that they share the victory with the players on the pitch.

"Regarding the way he was dressed on the night, he was free to dress how he wanted."

Wenger added: "For us it is important we focus on a big game against Newcastle tomorrow.

"We are ready to co-operate, but for us that is the end of the matter. What is important is our strength, and how well we focus.

"We have a fantastic spirit in the side. We can live with the comments made about us and show our behaviour on the pitch is spot on, which is all we can do."

Brown also hit out at Wenger after the match, claiming he had tried to get Hull players booked for time-wasting and had refused to shake his hand following their previous encounters this season - a statement which proved to be incorrect.

Wenger, however, remained phlegmatic.

"I have learned to be tolerant with the statements of managers after games, especially after defeats, so I do not make too much of it," he said.