Relief from temple of Hatshepsut returned to Egypt

AP circulated a press release last week noting that a relief stolen from the temple of Hatshepsut in 1975 had been returned to Egypt from London (e.g. "Egypt receives ancient stolen limestone relief", Daily Mail December 20, 2016). It appears that the relief had been purchased from a gallery in Spain by a London based dealer.

Which gallery in Spain?

I am particularly interested in the identity of the London dealer as due diligence in the London market is a major theme of the APPG on Cultural Property.