Budding young rugby league star Sonny Fai is missing, presumed drowned, after trying to save his brother’s life in dangerous surf near Auckland on the weekend.

The New Zealand Warriors back rower is believed to have been caught in a rip in the water at Bethell’s Beach in west Auckland after going on a training run with some friends and family members on Sunday evening.

The 20-year-old went into the water to cool off with his friends, but the group soon got into trouble with the strong currents about 8pm.

Mr Fai’s sister, La Lelei, told a New Zealand website that he had been swimming with his brother, cousin and his girlfriend Jenna Frost, and that all but two of the group had managed to make it safely back to the beach.

"I have a younger brother and a younger cousin that are a bit too weak, they couldn't swim that hard so some of the bigger boys and Sonny jumped in to save them," she said.

"I heard that they were all together, holding hands, but then somehow my younger brother drifted away from them and Sonny went back to get him”.

She said that Sonny had told his brother to let go of his hand which enabled him to drift back to shore.

"My younger brother came back and Sonny was taken out by the wave," La Lelei said.

Surf life saving rescuers on inflatable boats were joined by family members, including Ms Frost, who searched the beach for the missing sportsman until 1am this morning.

The NZ Warriors squad, which was due to officially begin pre-season training today, also joined in the search for their missing team-mate at first light this morning. However despite the air and sea search along the rugged coastline, Mr Fai remains missing.

Mr Fai’s agent Frank Endacott told a New Zealand website it was “not looking good for Sonny”.

Mr Fai signed with the New Zealand Warriors when he was just 14 and with his strong build, the 1.92m tall, 109kg sportsman has long been touted as a rugby league player with enormous potential.

The popular player, who has a fan club on the social networking site Bebo, played 15 games for the Warriors last year after making his debut with the club in Australia’s National Rugby League competition last March.

Bethell’s Beach is popular with tourists and as a filming location for TV shows and movies, however it can be a dangerous recreational spot. Just last month two rock fisherman drowned after being swept into the sea by the dangerous conditions.