The trio were being held in custody after the discovery of the body of a man in his 60s on Richmond Road on Wednesday.
But following “new information” as part of the police’s investigation, the death is no longer being treated as suspicious.
The three men, aged 37, 41 and 43, and all from Southampton, have been released.
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It follows officers going door to door in the Freemantle area to speak to residents yesterday, after five police cars were seen on Richmond Road at the peak of the incident.
A spokesperson for Hampshire police confirmed: “Following new information as part of our investigation into the death of a man in Richmond Road, Southampton, on Wednesday (July 16), three men who had been arrested have been released with no further action taken.
“We have been conducting enquiries into the cause of death of a man in his 60s from Southampton, and based on all the evidence available to us we are no longer treating his death as suspicious.
“The exact cause of death will now be a matter for the coroner, and we will continue to prepare a file for them.
“His family have been informed of this update and have been supported by officers.”