The theft happened at Lakeside Sports and Social Club, in North Moor Lane, between 8pm and 8.30pm on Wednesday, May 30.
A spokesman for Northumbria Police said: "A group of men entered the pub and used an unknown device to open up a fruit machine.
"Money was subsequently removed from the machine and the men left.
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"Enquiries are ongoing, and police have now released pictures of four men who they want to talk to in connection with the investigation.
"They were in the area at the time of the offence and could assist police."
The men, or anyone who recognises them, are asked to contact Northumbria Police on 101 quoting reference 1129 300518 or Crimestoppers anonymously on 0800 555 111.