In a bid to take down Ali Neeson, and stop him from getting back with Maria Connor, Gary hired an unnamed Private Detective to dig up dirt on his nemesis - but where have you seen the actor before?
The detective, played by Alexander Kirk, has made a couple of appearances in the soap and even helped Gary kidnap Big Farmer - the man who stole and sold NHS medication to doctors.
What other TV shows has he made appearances in?
He is well known for his role Jim in Mount Pleasant.
Alexander played the character in the show's first two series.
Shortly after his son Gary, played by Britain's Got Talent Winner George Sampson, came to live with him and his wife Bianca, he was killed when a remote control plane drove into his face.
The actor made an appearance in EastEnders back in 2008 playing Mal, an agent who was interested in Jane Beale's stand-up act.
Last year he appeared in Casualty playing Isaac Gowers.
He has also made appearances in Fresh Meat, Peep Show and played multiple characters in Drunk History: UK.
Currently jealous Gary has been after information on Ali as he used to date his new girlfriend Maria.
Noticing he wasn't over his ex, Gary wanted to make sure he got the information he needed to make sure Ali stayed away.
From the Private Detective, Gary found out that Ali was buying medication from Big Farmer.
Coronation Street is on Monday, Wednesday and Friday at 7.30pm and 8.30pm.
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