Witnesses told the Illawarra Mercury the rugby league and rugby union international leapt over a 1m-high concrete barrier in the middle of the freeway to rescue the 12-month-old and her mother, whose vehicle had collided with a truck near Bellambi Creek just after 5pm.

Sailor, 33, was returning to his Sydney home after training with St George Illawarra at WIN Stadium, when the accident occurred on the southbound side of the highway.

Wollongong Chief Inspector Ken McDonald last night confirmed Sailor's involvement.

A witness to the accident, Harry, said Sailor pulled over when he saw the accident and rushed to assist.

"I was travelling behind the lady, who was in a Holden Astra, and I swerved past the accident and pulled up," Harry said.

"By the time I got to the car Wendell Sailor had got the baby out of the back seat and was holding it and comforting the mother, who was pretty shaken."

The truck had collided with the driver's side of the car on a bend.

"Once everything had calmed down Wendell started clearing bits of the bonnet and other pieces off the road," Harry said.

"The mother and baby were pretty lucky. I just wondered where the hell Wendell came from - he was so quick - but you have to admire him for taking the risk to help out."

Perry Brothers tow truck driver Peter Jovcevski, who attended the accident, said Sailor then waited until police and ambulance officers arrived.

"He seemed to be making sure everyone was all right," Mr Jovcevski said.

"Being a family man I guess he was a bit concerned to see what happened. Then once everyone arrived and he spoke to the police, he walked back down the road a bit, crossed and drove off."

An ambulance spokesman said no-one involved in the accident was injured.

Sailor has had a hectic return to the sporting world after a two-year drug ban for cocaine use when contracted to the NSW Waratahs.

Hardened commentators, who have seen athletes disgrace themselves time and again, have given Sailor rave reviews for his determination to clean the slate.

He scored two crucial tries in his rugby league comeback game for Shellharbour Marlins in the Jim Beam Cup on Saturday in front of his family and thousands at the ground.

After the game he declared: "I've still got it."

St George Illawarra fans are now hoping he can soon help rescue their side.