Police officers were deployed to a Sheffield estate to search for a gun.
Police chiefs have revealed that officers were needed after a reports that a gun had been seen.
They searched a home in a bid to find the alleged weapon but nothing was found.
Instead, a 17-year-old boy was arrested on suspicion of possession of a Class A drug with intent to supply.
A South Yorkshire Police spokeswoman said: "Police executed a warrant in the Batemoor Road area of Sheffield following a reported sighting of a firearm.
"The officers were deployed to ensure no risk to the public and identify anyone suspected of carrying a firearm.
"A 17-year-old boy was arrested on suspicion of possession with intent to supply a Class A drug. He remains in custody.
"No firearm has been recovered and at this time, the reported sighting cannot be confirmed."