AN ACCUSED child predator, who sparked a manhunt following two violent kidnapping attempts in Sydney earlier this year, has been remanded in custody.

Late Sunday, detectives from the NSW Sex Crime Squad arrested the 49-year-old man at his home in Castle Hill.

Police allege he is responsible for the brazen attacks on two young girls in February and April.

On the first occasion, a man allegedly snatched a six year-old girl from her scooter in South Turramurra, before he was stopped by onlookers and fled into nearby bushland.

Two months later, a 14-year-old girl was walking across a footbridge at a Westleigh when a man allegedly grabbed her by the throat, threatened her with a knife and dragged her into the bushes.

The girl told police she escaped when the man was distracted by passing walkers.

Following Sunday's arrest, the man was charged with a string of offences and refused bail.

Sex Crimes Squad Commander Detective Superintendent John Kerlatec said public tip-offs played an integral part in making an arrest.

He described the investigation as "exhaustive" and commended detectives and the community for their work in netting a suspect.