Benning was born in Montréal, Québec and was hired by the Allied War Supplies Corporation (a Crown company) on the recommendation of his brother-in-law, Harold S. Gerson. Documents procured by Igor Gouzenko indicated that Benning had provided confidential documents directly to one of the members of the Soviet embassy. In accusing Benning of violating the Official Secrets Act, the espionage commission depended a great deal on section 3 (2) of the Official Secrets Act that allowed someone to be found guilty based on their known character. In this case, Benning's political (communist) beliefs. Another section of the Official Secrets Act stated that the burden of proof was on the accused. Both sections came under heavy criticism by the appellate court and Benning, who was found guilty at trial, had his sentence dismissed on appeal. At his appeal hearing, the judge argued that the state, in passing the Official Secrets Act, never intended to place the full burden of proof on the accused, and that the Crown needed more direct evidence to sustain a conspiracy charge.  

The espionage commission's final report writes of Benning:

"This man, who was born in Montreal of parents born in Newfoundland, entered the employ of Allied War Supplies Corporation, a Crown Company, in June, 1942, taking an oath of secrecy on July 7th "not to divulge any knowledge or information obtained by me in the course of my employment to anyone not employed by this Corporation unless expressly authorized by my superior officers". Shortly thereafter he was transferred from Montreal to the Department of Munitions and Supply in Ottawa. Benning had been hired by Allied War Supplies Corporation on the recommendation of Harold S. Gerson, his brother-in-law, upon whom we are also reporting. His service with Allied War Supplies Corporation was for training purposes only. It was understood that he would shortly go to Ottawa."