A roll of film found in the camera of Louise Kerton, a British student who vanished more than a year ago in Germany, could provide detectives with vital new clues to her disappearance.
The 24-year-old student nurse, from Broadstairs in Kent, had arranged to travel home to Britain by Hovercraft and then meet her fiancé in Dover on 30 July last year. But she never arrived.
A German version of Crimewatch screened on Friday night revealed that police have now stepped up their investigation in the light of new evidence.
This includes a series of photographs developed from film left in Louise's camera which police discovered at her boyfriend's home in Germany.
The pictures show groups of people, some elderly, sitting on terraces, relaxing or having drinks in the sunshine seemingly in a village in the region of Bad Zwischenahn, Lower Saxony.
But it is unclear who took the pictures and investigators said there was no reason for them to have been taken with Louise's camera. They made a television appeal for the people in the photographs to contact them.
They also made an appeal for all passengers to contact the police who travelled on the train that Louise is believed to have caught on the day of her disappearance.
In an interview with police, Ramana Simon, the mother of Louise's fiancé Peter, claimed she drove Louise to Aachen station to catch the 12.04 train to the Belgian port of Ostend and described watching her heading for platform eight.
German police originally treated Louise's disappearance as routine after they received unconfirmed reports that she was living in a hostel for the homeless in Aachen.
But in June this year they reopened the case as a criminal investigation instead of a search for a missing person. Last month, some 200 officers with sniffer dogs carried out an extensive search of countryside near the village of Strassfeld where Louise had been staying with her fiancé's family.
They were drawing on a dossier of information supplied by two former senior British detectives hired by Louise's father Phil at a cost of nearly £30,000.
The dossier challenged the account that Mrs Simon gave to police of Louise's movements on the day she went missing.
Mr Kerton said that going off of her own accord was entirely out of character for Louise, a former classmate of Lucie Blackman, the British bar hostess murdered in Japan. He has complained that important witnesses have not been properly questioned. These include Peter Simon's brother Michael who suffers from schizophrenia and was acquitted of murdering a 79-year-old woman in Broadstairs, Kent, in 1993.
"Her fiancé's family said we should keep her disappearance quiet at first in case she turned up," said Mr Kerton, a businessman.
"But they get very aggressive when I did go to the police. Those directly involved in this case have behaved very bizarrely."
He added that Louise had talked about splitting up with her boyfriend, whom she met at an ice rink when she was 16, shortly before announcing her engagement.