Sunderland have officially sold Jeremain Lens to Besiktas for a reported fee of £6m after the Turkish club triggered a clause in his loan deal.
The Dutch winger has been at Vodafone Park since the summer on a deal that was due to run through until the end of the campaign, making 20 appearances in all competitions.
Besiktas have now exercised the option to land Lens on a permanent move once the transfer window reopens, bringing an end to the 30-year-old's spell at the Stadium of Light.
A statement on Sunderland's official website on Wednesday evening confirmed the news, ensuring that the £12m signing from Dynamo Kiev in 2015 is now off their books for good.
According to the Sunderland Echo, the £6m handed over by Besiktas includes the initial £1.3m loan fee agreed last summer.