The gallery had given Drewe access to its archives which he then used to forge documents authenticating fake modern paintings that he then sold.[17] In 1998, Sir Nicholas Serota, director of Tate, conceived 'Operation Cobalt', the secret and ultimately successful buyback of two of the Tate's paintings by J.M.W. Turner that had been stolen from a German gallery in 1994. See Frankfurt art theft (1994). In 2006, it was revealed that the Tate was the only national-funded museum not to be accredited by the Museums, Libraries and Archives Council (MLA), as it did not wish to abide by guidelines that deaccessioned work should first be offered to other museums.