Kaboul seals return to Spurs
The 24-year-old is rejoining the north London club where he played 29 games and scored four goals in the 2007-08 season.
"We are delighted to announce that we have reached agreement with Portsmouth for the transfer of Younes Kaboul to the club." Spurs announced on their website.
Kaboul made 50 appearances for financially-troubled Portsmouth, who have been paid 5.0 million pounds for his signature according to media reports.
Having scored five times for the south-coast club, Kaboul links up again with Spurs manager Harry Redknapp who signed him for Portsmouth while he was manager there.
Kaboul, who joined Spurs from Auxerre in July 2007, becomes the fourth player to move from Portsmouth to Tottenham in the last year after Jermain Defoe, Niko Kranjcar and Peter Crouch.
Defoe and Crouch rejoined Spurs from Portsmouth, although Crouch was at White Hart Lane as a junior and played for several other clubs including Liverpool before moving back to Spurs.