Officers were called to Caunce Street in the town at about 10pm on April 6 after a 31-year-old man was found dead inside a room at a block of flats in Caunce Street.
However, following a forensic Home Office post mortem examination conducted on April 7, the cause of death is no longer believed to be suspicious and a file will now be passed to the coroner.
Ten people, aged between 37 and 60, who were arrested on suspicion of murder have been released without charge.
Earlier in the day, police said the man, found dead inside the suspected Blackpool drugs den, had suffered ‘unknown physical injuries’.
The 31-year-old’s body was found after a resident in the block of flats, in Caunce Street, central Blackpool, called 999.
The building, near to the junction with Grosvenor Street, had a number of drug users inside, police sources said.
Officers yesterday stood guard at the block of five flats, where an upstairs window was smashed and boarded up, while another had a curtain draped through the opening.
One man, who was yesterday working to renovate a property nearby, said: “There’s always trouble there; the police are forever there.
“They hang out the windows and climb out. It’s been going on for more than a year.
“The street is generally OK though.”
Lancashire Police would not say whether officers had been called to the property before however.
Detectives were set to apply for more time to question the 10 arrested people, but all were released following the findings of the post mortem examination.