The St James crematorium was not destroyed or damaged by fire and is still standing and doing cremations as of Wednesday morning.
Videos and photos circulated on social media on Tuesday evening suggested the building was on fire.
Speaking with Newsday, acting Chief Fire Officer Marlon Smith confirmed while the fire service had received a report of a fire at the building, neither the staff nor the building was in danger.
Smith said officers from the St James Fire Station found the building intact.
"We visited the location but it turned out to be a regular exercise at the site, so there was no cause for us to extinguish any fire.
"What happens is from time to time, depending on the fat content of certain bodies, it might ignite and flare up, giving the impression that the building is on fire. Which is what happened when people saw the outside of the building."
Asked if this posed a possible fire hazard to the building or its surroundings, Smith said crematoria are generally located in areas with some degree of isolation and were subject to a rigorous inspection process by the fire service to ensure workers' safety .
Newsday spoke to deputy Port of Spain mayor Hillan Morean, who also confirmed there was no damage at the crematorium, but noted the building has been working at full capacity to accommodate the cremations of people who have died from covid19.
He said as a result of this workload, the flames and smoke from the chimney made it appear to distant residents that the building was on fire, but wanted to assure the public that this was not the case.
"Port of Spain has no approved sites for covid19 burials so they (the crematorium) have been working quite a lot these days because of covid deaths.
"I know the crematorium has been doing much more now, so that would have been part of what led to the thick smoke we saw."
Morean said residents in the area would have raised some concern over the smoke from the chimney, anda report has been requested from the management.
"Public health and safety is a high priority for us. We have an institutional committee meeting tomorrow (Thursday), so that will be raised, and we will decide what can be done next."