Over eight years, Larsen conducted several meetings with the CIA where he gave information on the relationship between the Soviet Union and communist parties in other countries. He was asked if the Communist Party of Denmark was doing espionage work for the Soviets or if the party was preparing an illegal party apparatus. He denied direct knowledge about this, but told the agent that the party had turned down Soviet and East German requests for aid with espionage. According to some of Hansen's sources, Larsen was rewarded with vacations, dinners and money for his co-operation.