Police are renewing an appeal to locate a man missing in the Blue Mountains after his backpack was located.
Mathieu Petiot, a 24-year-old French national tourist, was last seen leaving Katoomba Railway Station just before 2.30pm on Monday, November 6.
Police hold grave concerns for his welfare.
He has been described as being of Caucasian appearance, thin and 165cm tall.
Mr Petiot was last seen wearing a black jumper, navy blue jeans and dark shoes.
Mr Petiot was seen carrying a dark grey and black-coloured backpack which was later located at the Echo Point lookout at Katoomba.
Anyone who sees Mr Petiot is urged to come forward and contact police.