A US national has died after a spearfishing trip went wrong on Sydney’s Northern Beaches.

Police said the man, believed to be aged in his 40s, was spearfishing with a 20-year-old man known to him when the pair became caught in a rip at Shelly Beach in Manly on Tuesday afternoon.

Emergency services were called to the beach about 2.50pm after the pair were pulled from the water, with the older man unconscious.

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Paramedics performed CPR before taking him to hospital, where he later died.

While he is yet to be formally identified, police have been told he was a US national.

A swimmer has died after a spearfishing trip went wrong. Credit: Cheryl Wilson

The younger man was not injured.

Police have launched an investigation into the circumstances surrounding the incident.

A report will be prepared for the coroner.