A man who told police his friend had been shot dead "laughed" after officers arrived to find no signs of disorder.
Police received a 999 call at about 00:30 BST alleging a shooting had taken place at shared accommodation on Frances Road in Erdington, Birmingham, in which a man had been killed.
Armed officers were "swiftly dispatched", West Midlands Police said, but found no evidence of a shooting.
A 26-year-old man was arrested on suspicion of wasting police time.
The force said after the man was called back, the handler heard a man "laughing" before he denied calling emergency services.
The 26-year-old from Erdington remains in police custody.