Matrix has hit rival set Doughty Street Chambers for human rights silk Richard Hermer QC.
Matrix said the addition would bolster its public law credentials.
Hermer has been instructed in a number of high profile cases. Most recently he was instructed to act for four Mau Mau Kenyans in their bid to win compensation from the UK Government over allegations that they were victims of British atrocities committed during the Mau Mau uprising in the 1950s (21 July 2011).
Hermer has also been involved in the long running Trafigura litigation, instructed by Leigh Day & Co during the ongoing costs dispute spinning out of the settled case (12 October 2011).
He also represented the family of Baha Mousa and most of the former UK citizens and residents released from Guantanamo Bay in their claims against the UK Security Services.
Currently he is instructed by more than 200 Iraqi citizens who are looking for compensation following allegations of torture and mistreatment.