Southampton's transfer of Vitesse Arnhem defender Alexander Buttner is on the verge of collapse.

The newly-promoted Premier League side were expected to finalise a deal for the Dutchman after agreeing a deal to take the player to St Mary's.

Despite a proposed switch, it appears that negotiations between both parties have broken down, which spells uncertainty for the 23-year-old.

A statement on the club's official website said: "The transfer of Alexander Buttner to Southampton is uncertain. Last Friday, Vitesse reached an agreement with the Premier League side for the transfer of Buttner.

"As Buttner had already agreed personal terms, it was expected that a medical was the only thing that could block the deal. Over the weekend the player let us know through his agent that there was an additional demand from a third party.

"Vitesse are disappointed at the current state of affairs, especially because negotiations with Southampton were opened on the demand of the player. Southampton FC has played everything correctly and don't take any blame in the undermining of this transfer."

The third party, who has disrupted talks with the Saints, has not been made known.