A picture of Cambridge educated Russian spy Donald MacLean, associated with a group of Cambridge Univerty spies including Guy Burgess, Kim Philby, John Cairncross and Anthony Blunt, pictured with his two sons. [Getty Images]

A picture of Cambridge educated Russian spy Donald MacLean, associated with a group of Cambridge Univerty spies including Guy Burgess, Kim Philby, John Cairncross and Anthony Blunt, pictured with his two sons (Photo by Popperfoto via Getty Images/Getty Images) — see more

A picture of Cambridge educated Russian spy Donald MacLean, associated with a group of Cambridge Univerty spies including Guy Burgess, Kim Philby, John Cairncross and Anthony Blunt, pictured with his two sons (Photo by Popperfoto via Getty Images/Getty Images)