John Stevenson Wright was sentenced at Manchester Crown Court to 18 months for sexually abusing Darren Kenny.
The court heard the offences took place when Wright worked at a pub run by Mr Kenny's parents in Rochdale.
Wright, 68, abused Mr Kenny as a teenager when he used to sleep over at the pub.
He was convicted of gross indecency, indecent assault and inciting a child under 16 to engage in a sexual act between 1978 and 1981.
Wright's sentence will be added to the 22 years he is already serving for sexually abusing boys.
Mr Kenny, 50, an officer with Greater Manchester Police in Tameside, was repeatedly abused as a teenager and thought Wright was dead until he typed his name into an internet search engine.
While looking for his abuser's obituary, he was "horrified" to learn Wright had been jailed for child sexual abuse in Rochdale.
He added: "We had been told he had died - I had my closure and then when we found out he wasn't dead I had no closure any more and I needed it back."
Mr Kenny, who has waived his right to anonymity, contacted the officer who had investigated Wright and said: "I've got another victim - me.
"Even if wasn't a policeman I would have come forward.
"The length of sentence isn't important... returning the guilty verdict is what is important."
Mr Kenny encouraged other abuse victims to speak out.
"Look at me - I'm here, I'm a 50-year-old cop, and if I can do it I'm sure they can."
A police officer who thought his childhood abuser had died before he chanced across him online has said the man's conviction brought him "closure".