Friends of Xun Xu are appealing for help from members of the public after the woman went missing in the early hours of Saturday morning.
The woman was returning from Turku in Finland to Stockholm with three friends at the time of her disappearance. At around 6am on Saturday, she told her friends that she was going up on deck to watch the sunrise.
But she did not return to the cabin and her purse and other personal possessions remained untouched when the time came to disembark from the ferry.
"We don't want to consider the possibility that she might have fallen into the water," Chen Zhipeng, a friend, told The Local.
Jackie Moberg with the missing persons unit of the Stockholm police confirmed the disappearance.
“She has been reported missing but since then we haven’t had any new information,” she said.
“I’ve also been in contact with the police in Finland and asked them to look into the matter. They had no knowledge of the case when I called, but are currently checking hospital registries and other places in search of any information about her.”
Moberg added that police have requested security camera tapes from the boat, but must wait for it to return to port in order to review the footage.
Xun Xu has previously studied as an international master’s student at the Royal Institute of Technology (KTH) in Stockholm.
She currently works for a Dutch company and had returned to Sweden to visit friends. She was scheduled to fly back to the Netherlands on Monday.
Xun Xu is 1.67 metres tall. She was wearing a V-neck sweater with grey and black stripes, a purple scarf and long brown boots at the time of her disappearance.
Anybody with information pertaining to the case is asked to contact the police at 114 14 (or +46 77 114 14 00 outside Sweden).