An Australian man who cycled around Europe looking for his missing son has returned home to Sydney with the six-year-old boy.

Ken Thompson quit his job as deputy New South Wales fire chief and cycled across Europe looking for his son Andrew.

The boy was taken out of the country at the age of three by his mother during a custody dispute.

Mr Thompson has called on the Federal Government to overhaul child abduction laws and make it a crime to take a child out of the country without permission.

"Now it's not about finding a way to punish a parent who's taken a child, it's about finding a way to enable the authorities to help you find the child," he said.

"The Australian authorities cannot help you, particularly the Australian Federal Police cannot help a parent whose child has been abducted locate that child, because a crime has not been committed."

The father and son were reunited late last year and with the permission of Dutch authorities flew into Sydney last week.

Mr Thompson says they are glad to be home.

"However, I'd now like to ask the national and international media to please respect Andrew's privacy and give him a chance to be a normal, little Aussie boy," he said.

It is understood Andrew came to the notice of authorities when he was enrolled for school in Amsterdam.

Mr Thompson said at the time of the reunion he wanted to devote the rest of his life to helping other parents find their abducted children.

"Don't give up hope. It's hard work when you can't really get the authorities to help you," he said.

"I'm not being critical of the authorities, they're just not empowered to do it."