New South Wales Police have been told the fire at a marina on the Murray River at Moama started on one boat and spread quickly to remaining eight.

Officers attached to Deniliquin Local Area Command established a crime scene and commenced an investigation this morning.

Inquiries into the circumstances are continuing.

Police are urging anyone with information to call Crime Stoppers on 1800 333 000 or use the Crime Stoppers online reporting page https://nsw.crimestoppers.com.au/

EARLIER: About 10 houseboats have been destroyed in a fierce fire at a marina on the Murray River at Moama.

New South Wales Rural Fire Service and Fire and Rescue NSW crews were called to Deep Creek Marina on Perricoota Road about 6.15pm on Thursday evening and found a number of houseboats well-alight.

NSW RFS Inspector Ben Shepherd said about 10 houseboats were destroyed, while about 10 were saved after they were cut loose from their moorings.

A small grass fire also broke out at the site as a result of floating embers.

Fire and Rescue NSW zone commander Stewart Alexander said conditions were difficult for firefighters, given the intensity of the blaze and the fact they could not get onto the vessels.

The fire was so great that the plume of smoke could reportedly be seen in Deniliquin.

Mr Shepherd said firefighters had the situation under control within about two hours, although the fire continued to burn into the night.

Mr Alexander said Fire and Rescue firefighters were at the scene until about 1.30am.

A small amount of fuel spilled into the water as a result of the fire.

Mr Alexander said the agency, with the assistance of Marine Rescue NSW, deployed booms to limit the spillage.

No one was injured during the incident.

Mr Shepherd said initial reports from people at the scene suggested an air conditioner on one of the boats might have been to blame for the fire, although RFS investigators would try to determine the cause.