An aerial search off Heron Island has failed to turn up any evidence of two people aboard a life raft.

An aircraft overflying the area on Saturday night, approximately 200 kilometres east north east of Heron Island off the central Queensland coast, identified something in the water on its radar.

While no visual fix of the object was made, an Australian Maritime Safety Authority aircraft was tasked to the area and its crew, using the aircraft's forward looking Infra-red (FLIR) thought they had sighted two men in a life raft.

"The Australian Maritime Safety Authority went out with their Dornier and they thought they saw a life raft with two men on board," RACQ CQ Rescue spokesman Phillip Dowler told AAP.

"No one's actually sighted anything," he said.

The RACQ CQ Rescue helicopter was tasked at 10pm (AEST) on Saturday to assist.

No EPIRB emergency location beacon has been activated.

A search of the area involving seven aircraft on Sunday morning failed to confirm the raft's existence.

Mr Dowling said the RACQ CQ Rescue helicopter will remain on Heron Island for the next 24 hours in case a rescue is required.

A relief crew is being flown from Mackay.