Officers recovered suspected Class A drugs during the raid at a bedsit on the corner of Compton Road and Larches Lane on September 3.
Three men, aged 46, 49 and 52 – along with a 50-year-old woman – were arrested on suspicion of possessing a controlled drug with intent to supply.
West Midlands Police spokesman Craig Hughes, said: "We recovered suspected Class A drugs after executing a warrant at an address in Compton Road, Wolverhampton, on September 3."
The four suspects been released under investigation while inquiries continue.
Officers were seen entering through the rear door of the property at around 5.30pm.
A short time later the first of the suspects was led out in handcuffs and detained in a waiting police van.