The Teessiders insisted on Friday the paperwork for the deal had not been completed after Middlesbrough's record signing Alves was pictured on the Al Sadd official website wearing a shirt and scarf.

But 11-times Qatar league champions have now confirmed the 28-year-old has agreed a three-year contract with Al Sadd able to sign players until September 15.

Middlesbrough had already confirmed an undisclosed fee, believed to be £6 million, had been reached.

Alves joined Middlesbrough for a club-record £12.7million from Heerenveen in January last year but failed to reproduce his Dutch league goalscoring exploits in England and managed just 10 goals in 42 appearances in the Barclays Premier League.

He has not figured at all this season after undergoing surgery on a broken foot at the end of the last campaign.

"It's a great honour for me to join a good team like Al Sadd who are one of the best clubs in Asia," said Alves.

"I have heard a lot about football in Qatar from my compatriot Felipe Jorge who is playing also with Al Sadd.

"I'm looking to be the top scorer of the Qatari league next season. I'm happy to have two other Brazilians in the team and hopefully we will be a successful trio in the league.

"I want to have great success with Al Sadd just like I did with Heerenveen in Holland in 2007 where I scored a lot of goals and I hope that I can do the same with Al Sadd."