Detectives are renewing their appeal for information in what has become a murder inquiry after the fire at Demesne Road in Douglas 10 days ago.
Terry Losh, 61, died in his flat in the early hours of Sunday, March 22.
On Tuesday, a man appeared in court charged with the murder of Mr Losh, and four counts of arson with intent to endanger life. Simon Leece was remanded in custody until April 7.
Police are looking for a man and woman who walked past the house shortly after 4am on the morning of the fire and want to speak to a man wearing a tuxedo in Kensington Road early that morning.
Detectives also want to hear from two people walking past Road and Track on Tynwald Street at about 3am.
Acting Detective Chief Inspector Kevin Willson is thanking the public in the area for their patience.