For decades the CIA has paid tribute to its fallen spies by placing a star in their honour on a memorial wall at its headquarters in Virginia.

Now, on the eve of a ceremony to commemorate two more of the agency’s heroes, a historian has stirred controversy by questioning the star given to an employee who committed suicide while serving in Afghanistan. “Suicide is a great tragedy, but this is not what the wall is for,” Nicholas Dujmovic, an authority on CIA history and now a professor at the Catholic University of America, said.

Ranya Abdelsayed joined the CIA in 2006 and was serving in Kandahar when she took her life in 2013 aged 34. She is the only officer to be given a place