Officers recovered the fake weapon after executing a search warrant in Hawthorne Crescent in Mexborough earlier today.
Detective Inspector Steve Smith said: “On further inspection, it was determined that this was an imitation firearm.
“Although it’s not capable of firing ammunition, the weapon certainly looked ‘real’ and could’ve easily caused fear and alarm if used to threaten members of the public for example.
“We’re pleased to have been able to recover it so that it could never be used for that purpose.
“This morning’s warrant is part of ongoing activity aimed at disrupting organised crime within the local area.”
The raid comes as Chief Superintendent Shaun Morley marked one year in the job as Doncaster’s district commander by highlighting some of the force’s crime-fighting successes.
He told how more than 100 search warrants have been carried out resulting in the arrest of more than 50 members of organised gangs.
Chf Supt Morley also believes a reorganisation of teams at Thorne, College Road and Mexborough, plus the return of CID to Doncaster and the protecting vulnerable people units, has seen positive results.
He said: “For you, as a resident of Doncaster, it means that officers can ultimately respond and deal with crimes more effectively to apprehend offenders and ensure victims receive the best service possible.
“With resources now based back in district, we have already reaped some of the rewards, with work carried out through the proactive and tasking teams within CID.
“Together, they have been focusing on tackling organised crime across Doncaster, which has been and remains one of our top priorities.
“The teams have executed over 100 warrants, apprehending over 50 of our key organised crime members.
“They have done an absolutely tremendous job, removing quantities of lethal drugs from our streets, and this in turn has led to a number of successful prosecutions and convictions.”