The investigation into the disappearance of English tourist Grace Millane has revealed several of her belongings are missing, including her passport.

Detective Inspector Scott Beard says an assessment has been made on the 22-year-old's belongings that were found at Base Backpackers Hostel where she was staying.

"Several of her belongings, including her passport are missing and police believe it is likely Grace has these items with her."

Police have also released photographs of her missing necklace and watch.

"Grace's watch is a pale pink Casio Baby-G and her necklace is described as silver and round with a green stone in the middle of it.

"Police would like to hear from anyone who has seen any items matching this description over the past week."

A scene examination at the Citylife hotel is continuing, says Scott.

"Detectives are continuing to view hundreds of hours of CCTV footage.

"At this point our enquiries have not led us to any further confirmed sightings of Grace, and the last known sighting is of her entering the Citylife Hotel at 9.41pm on Saturday December 1.

"Dozens of calls have been made to the 0800 number and all of this information continues to be reviewed and assessed.

"Many of these calls have been from members of the public, offering accommodation and assistance to the Millane family.

"Police continue to offer support to the Millane family, both in New Zealand and in the UK."

Grace has not been in contact with her family for about a week now. She arrived in New Zealand on November 20.

Prior to her dissapearance, Grace had been in contact with her family everyday and concerns were raised when she didn't respond to birthday messages on Sunday December 2.

Grace is a 22-year-old European woman with brown hair and brown eyes. She's approximately 5ft 6in (168cm) in height, and 58kg.

Anyone with information on her whereabouts or who may have seen the missing items above can contact police on: 0800 676 255.