A homeless man was busted this week for allegedly bludgeoning an acquaintance to death in the basement of an abandoned Bronx building, authorities said. 

Delroy Dunn, 56, was arrested at 10:25 p.m. Wednesday in connection to the death of Locksley Christie, 52 — whose partially decomposed body authorities found under plasterboard while responding to an Aug. 4 call for a foul odor inside the building on Briggs Avenue near East 198th Street in Bedford Park, police said. 

Christie died of blunt force trauma to the head, cops said. He lived a couple of blocks from the building where his body was found.

Video obtained by investigators last shows the victim alive on July 29 — and Dunn was the last person seen with him, police said.

Dunn was charged with murder, manslaughter and criminal possession of a weapon, cops said. 

The building had been under a full-vacate and stop-work order since a December 2016 fire, Buildings Department records show. 

An elderly woman and seven firefighters were hurt in the blaze, the Bronx Chronicle reported at the time. 

At least 10 people from five families were displaced.