Roman Garby-Czerniawski (6 February 1910 – 26 April 1985) was a Polish Air Force captain and Allied double agent during World War II who used the code name Brutus.

Czerniawski was evacuated to Britain to be examined by Polish intelligence, and met General Władysław Sikorski and was presented with the Virtuti Militari.

The network had been uncovered because of the lack of proper operational security within the organisation, and many other members of the Interallie were picked up after Carré had agreed to co-operate with the Germans in return for her life.

His strong anti-Soviet attitude, manifested in his denouncing in a pamphlet that he authored of a Polish officer who attended an official reception at the Soviet embassy, led to doubts about his suitability.

[3] MI5 doubted his reliability and thought him to be fickle and liable to meddle, and MI5 also harboured concerns that the Germans would be suspicious about his arrest and swift release.