Four vessels from Marine Rescue Port Macquarie along with a jet ski from surf lifesaving Mid-North Coast were involved in the search, which continued for more than two hours, after a sighting of a swimmer in possible difficulty near the Hastings River breakwall.

The report was raised after a man and woman were walking along the breakwall this morning and noticed someone swimming in the river.

The person, who they could not identify as either male or female, appeared to have blonde hair.

The couple did not have a mobile phone with them at the time, so the woman ran back to the police station on Hay Street to raise the alarm.

When the woman returned to the spot with police, no trace of the person could be found.

It could not be determined whether the person left the water of his or her own accord, so water police and the Westpac Rescue Helicopter were called in to sweep the area.

Marine Rescue spokesperson Geoff Shelton said it had been very handy all the appropriate agencies were on hand because of Australia Day festivities.

The search was called off when there was no sign of a body or swimmer in difficulty in the vicinity.