Borussia Dortmund have officially completed the signing of coveted Basel and Switzerland defender Manuel Akanji, believed to be for a fee in excess of €20m.

Akanji had been linked with Premier League club Southampton, as well as West Ham, ​Tottenham and ​Liverpool, but has joined ​Dortmund on a four-and-a-half year contract that will run until June 2022.

The 22-year-old centre-back, who played every minute of Basel's Champions League group stage earlier this season, has been assigned Dortmund's number 16 shirt.

"I felt very good in the talks with the Dortmund officials, so it was a decision from the heart" Akanji told ​ upon confirmation of his move.

"And I've always liked the football played in Dortmund," he added. "I'm looking forward to the time here and will do my best."

Manchester United v FC Basel - UEFA Champions League

Dortmund sporting director Michael Zorc commented, "Manuel has been a target for several top European clubs with his performances, and we are happy that he has chosen us.

"He has proven in the national team and in the Champions League that he can play at the highest European level. We also see him as a defender, who has further development potential."