The family of a young woman who went missing from a Disney cruise ship say the company was keen to keep her disappearance low key after they were taken to the ship in cars with blacked-out windows and ushered in through a rear entrance.

Rebecca Coriam's parents are calling for legislation to protect passengers and staff on ships.

Coriam, 24, from Chester, who was a youth worker on the Disney Wonder, has not been seen since 22 March when she disappeared during a week-long cruise from Los Angeles to Mexico. Her credit card is missing but has not been used.

Her parents, Mike and Ann Coriam, want the law changed so that the UK authorities would investigate such cases involving UK citizens. As the ship was registered in the Bahamas, a single officer from the Bahamas police force is investigating the case. The couple also want more CCTV cameras on cruise ships.

Six months after her disappearance, her parents told the Guardian of their daily struggle to keep going and retain hope that she is still alive.

A photograph of their smiling daughter in her yellow Disney uniform is on the mantelpiece at their home in the village of Guilden Sutton, Cheshire.

The Coriams are campaigning for a change in international law. Currently, crimes are investigated by the police force where the ship is registered.

Last week, they met the shipping minister Mike Penning, who is contacting the International Maritime Organisation on their behalf.

They speak of their happy, sporty, popular daughter who had everything to live for and who planned a surprise visit for her family to Disney Paris in April, when she was due home.