Cooke played for Hull on Friday and was a fan at Rovers on Sunday

The move was blocked by the league on Monday, but talks continued between the clubs' legal representatives.

The RFL said that it had been given evidence that Hull FC's legal advisors had accepted Cooke's resignation of 23 April with immediate effect.

But Hull plan to take legal action against Cooke for breach of contract.

The stand-off is set to make his Hull KR debut against Huddersfield on Friday.

A RFL statement said: "Based on clear legal advice from the RFL's external lawyers - we have determined there is no valid reason not to accept the registration of Paul Cooke as a player with Hull KR following the acceptance of his resignation by Hull FC."

But they added that allegations of misconduct against both Paul Cooke and Hull KR will be referred to the RFL Compliance Commissioner.

Despite the ruling, Hull insist they have not accepted Cooke's resignation.

606: DEBATE Give your reaction to Cooke's move

A statement from the club said: "Hull FC believe that the RFL have taken the resignation out of context.

"It is clear from the total content of all communications with Mr Cooke, Hull KR and the RFL that the club and their lawyers were objecting to the transfer of his registration and therefore not releasing him from his obligations to Hull FC.

"We do note that the RFL has confirmed our serious concerns about the manner of Paul Cooke's transfer to Hull KR and has referred it to the RFL compliance commissioner.

"We welcome the opportunity to meet the compliance commissioner.

"However, it is safe to say that, pending the outcome of that referral, we fully intend to pursue legal redress in court for breach of contract by Mr Cooke and claims against any other party which has assisted him in his actions."

Hull KR had left a place open in their squad to face Huddersfield in case Cooke's controversial move went through on time.

The 26-year-old, a lifelong Rovers fan, confirmed on Monday that he had handed in his resignation at the KC Stadium and was set to join Hull KR but Hull threatened legal action.

"I confirm that I have asked Hull FC to transfer my player registration to Hull KR and have notified the RFL accordingly," he said.

Hull FC had previously said an employment law specialist had confirmed they had a legally binding contract with Cooke, but he says he never signed the three-year deal they offered him in June.

"For some time I have been unhappy with a number of aspects of my contract with Hull FC and for that reason did not sign it," he said.

"After almost 10 years at the club, it is disappointing to leave in this way but all I can say is that I have enjoyed playing football for Hull FC and thank its thousands of fans for supporting me through the years.

"I am very happy with the contract arrangements that have been offered to me by Hull KR and now look forward to helping them maintain Super League status."

Cooke, rated the best uncapped stand-off in Super League, is Hull's joint longest-serving player, alongside Richard Horne, and has amassed 798 points from 221 appearances in his nine seasons with the club.

He has been their leading scorer in each of the last three years and was the hero of their 2005 Challenge Cup triumph over Leeds at the Millennium Stadium with the late match-winning try.