Try to consider Willy Lehmann. He was recruited in 1929, before Hitler came to power, initially for money, but when the War became expected to start, his collaboration became more ideological as he was strongly against it.
He headed the Gestapo department that was doing counter-intelligence against Soviet industrial espionage.
He transferred over a lot of very important info to the Soviets, that on German weapons, rocket technology, submarines, Gestapo cryptographic codes, and even the exact date for the invasion of the USSR.
When the USSR had lost link to him, he conducted a risky step, and in 1940 put a letter into a post box of Soviet embassy calling for continued collaboration and said his work in Gestapo would lose any meaning if the USSR would not resume contacts.
In 1941 after invasion of the USSR the connection with him was lost. In 1942 the Soviets tried to reestablish contact, but the Germans captured the sent communicators and executed Lehmann afterwards.