A 17-year-old Sydney girl has saved herself from being forced to go to Lebanon for an arranged marriage by calling the Australian Federal Police (AFP).

Federal police say the girl sounded frightened when she called them about a month ago. She said mother was out, but that she may have to hang up at any time.

She then explained her plight - her mother had booked her on a flight from Australia to Lebanon in mid-May, where she was to be married.

She said her father and step-father supported the decision.

The girl, who cannot be named, said she had heard about the airport watch list and wanted to be placed on it so that there was no way she would be able to leave the country.

The AFP took the matter to the Federal Magistrates Court which handed down its judgement last week.

It banned her family from taking her from Australia and ordered them not to threaten her.