Officers have confirmed the man killed in the blast was 50-year-old Graham Green.
Although formal identification is yet to take place, Mr Green's family have been informed.
Emergency services were called to reports of an explosion and fire at a block of flats on Alloa's Kellie Place at around 6pm on Sunday.
Three others - a 19-year-old man, a 72-year-old man and a 49-year-old woman - were all taken to Forth Valley Royal for treatment.
Enquiries into the incident are ongoing, and police say the death is currently being treated as unexplained.
Chief Inspector Kat Thompson, area commander, said: “Our thoughts remain with the family and friends of Graham and all those affected at this difficult time.
“Our enquiries, alongside partner agencies, to establish the full circumstances of what happened, remain ongoing.
“A police presence will remain in the area and I would like to thank the local community for their understanding and support.”
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