Stephenson Harwood has been replaced by Addleshaw Goddard as adviser to the former chairman of Kazakhstan's BTA Bank Mukhtar Ablyazov on a multibillion-dollar fraud case.

Addleshaws was formally instructed on the case earlier this month, with litigation head Richard Leedham now leading the case for the firm, alongside fellow litigation partners Ian Hargreaves, Jon Tweedale and Jamie Harrison.

Leedham said: "We were approached at the end of the summer to see if we would take it on.

"We're very excited to be involved in this, and although it is already at quite an advanced stage, we've got the resource to handle it, with around 30 litigation partners in the group."

The move will see Stephenson Harwood lose out on significant revenues from its work on the case. The firm had a team of five partners working on the account including commercial litigation trio Roland Foord, Alan Bercow and Richard Gwynne, arbitration head Louis Flannery and corporate insolvency and restructuring head Stuart Frith.

Ablyazov, who served as BTA's chairman from 2005 to 2009, is facing claims from the bank for alleged fraud over the misappropriation of assets. Ablyazov fled to London in 2009 when the bank was given the go-ahead to be nationalised.

Hogan Lovells is acting for BTA, with a team led by litigation partner Chris Hardman.

Addleshaws is also currently acting for Russian oligarch Boris Berezovsky in his multibillion-pound claim against Roman Abramovich.