A 30-year-old man arrested in connection with the murder of 71-year-old Adam Krzan has been released from custody unconditionally, police said.
Mr Krzan was found with serious injuries at a flat in the Corrainey Park area of Dungannon, Co Tyrone on February 27, and later died.
The Police Service of Northern Ireland launched a murder inquiry.
A 33-year-old man, arrested on suspicion of murder, and a 27-year-old woman arrested on suspicion of perverting the course of justice both remained in custody on Wednesday evening.
A second 30-year-old man has been released on bail pending further inquiries.
Detective Chief Inspector Graham Orr has urged anyone with information about what happened to Mr Krzan to speak to police.
“My thoughts at this time are first and foremost with Mr Krzan’s family and friends who are left trying to come to terms with their loss,” he said.
“Our investigation is at an early stage and enquiries are ongoing to establish the exact circumstances.
“I am asking anyone with information, no matter how insignificant it may seem, to contact detectives on 101. Please quote reference 1576 of 27/02/25.”