Two men have tragically lost their lives, and a woman has been hospitalised following a swimming incident in an Australian river.

Emergency services rushed to John Locke Place in Gleniffer, approximately 530 kilometres north of Sydney, at 6.45pm on Sunday, January 25. Reports indicated that the trio, all in their 30s, were struggling while swimming in the Never Never River, The Mirror reports.

A spokesperson for New South Wales Ambulance revealed that crews responded to reports of three individuals being "submerged under the water".

The woman was rescued from the water and given immediate treatment at the scene before being transported to hospital in a serious condition - the Daily Mail reports she is expecting.

Despite efforts to save them, the two men could not be revived after being pulled from the water and were pronounced dead at the scene.

The Never Never River is a favoured spot for swimming. It's common for tourists to pitch camp along the riverbank and enjoy a dip in the water.