FC Groningen chief Hans Nijland has confirmed Celtic defender Virgil van Dijk has signed with Southampton.

Van Dijk is a former Groningen player.

Nijland tweeted: "Just received a nice message from (Southampton manager) Ronald Koeman.

"We congratulate Virgil van Dijk wholeheartedly with his transfer to Southampton. A very nice and deserved transfer!

"The brothers Koeman, Tadic and now Virgil van Dijk. Beautiful!"

Saints are coughing up almost £12 million for Van Dijk.