The Cameroon international midfielder agreed to join the Riverside outfit last Friday on a one-year loan deal from European champions Real Madrid.

But he had to return to Spain while the Department of Employment considered Boro's application for a permit.

Their request was granted in view of the fact the player has more than 50 caps to his name.

"This is great news," manager Steve McClaren told the club's official website.

"Although we didn't anticipate problems, it's always good when these things are resolved swiftly and positively."

McClaren secured Geremi's signature after talks between the player and Chelsea broke down over money.

He has an option to make the 23-year-old's move permanent at the end of the season, and insists his quest for new personnel is far from over.

The Boro boss has already signed Italian striker Massimo Maccarone, made Franck Queudrue's loan move permanent and continues to track Brazil's Juninho and Aston Villa's Dutch international George Boateng.

"Geremi's a quality player who can play anywhere in midfield," he said.

"I'm delighted to have finally signed a player that I first wanted last summer, especially as several other top clubs were interested in him.

"He's a good athlete, strong and quick. He's got an excellent footballing pedigree, with great experience at both club and international level.

"We've got him from the best team in Europe and, at 23, he's the right age too. I'm very pleased."

McClaren added: "We're continuing to work hard to bring in more players for the new season."