Anderson lost patience with the London Broncos

The Broncos announced they had signed the 26-year-old in February but the Rugby Football League blocked the deal amid worries over the club's finances.

"He wanted to get his life sorted out," admitted London chief executive Nic Cartwright. "We wish him all the best."

Second-rower and centre Anderson signed a three-year contract with Saints.

Anderson, who was released from his contract by New Zealand Warriors, played alongside his younger brother Louis in the Gillette Tri-Nations Series and made his Test debut against Australia in October 2003.

"It's a major coup for us," said St Helens chairman Eamonn McManus.

"He's perfect for us and the last piece in the jigsaw.

"He's a hard-running second rower who can play in the backs as well. He's also a young international coming to Super League which is a rarity."

Anderson, who should make his debut against Salford on Friday, will fill the hole left by fellow Kiwi Michael Smith.

Smith failed to settle at the club and left before the start of the season without playing a competitive match.

On Monday, the day the register for the Powergen Challenge Cup closed, Smith joined Hull KR.

England Under-19 rugby union centre Chris Rhys Jones also signed for St Helens.

The 21-year-old will not arrive at Knowsley Road until his Sharks contract expires in June.

"We've been watching Chris for some time," said McManus. "We feel he will make a better league player than a union player.