DLA Piper's former Turkish arm Yuksel Karkın Kucuk (YKK) was raided by the police and lawyers have been taken into custody in the aftermath of the failed coup in Turkey, according to local press reports.

YKK merged with DLA Piper in 2010 but the two firms split in 2014, although they have continued to work together in a non-exclusive referral relationship.

According to local news reports, the firm – the largest in Turkey – was raided by the police last month and four lawyers were taken into custody, although Legal Week understands they have all since been released.

The firm is not currently open and its website has been taken down. It is not clear whether it will reopen.

A DLA Piper spokesperson said: "The firm terminated its formal relationship with YKK by mutual consent in November 2014 but we have continued to work together on a non-exclusive basis, as well as working with other local firms.

"We are aware that YKK has been closed for over a week and we have been assisting our clients to obtain alternative support where necessary."

Turkish president Recep Tayyip Erdogan has blamed the 15 July coup attempt on the followers of religious and political leader Fethullah Gulen, who currently lives in exile in Pennsylvania.

In the aftermath of the failed coup, the Turkish government has cracked down on those suspected of links with the Gulenist movement, purging the judiciary, army and the police.

The Turkish government has also sought the extradition of Gulen from the US, although Gulen denies any connection to the attempted coup.