Swiss police said Friday a massive operation to find missing twins kidnapped in January by their father had failed to uncover any new evidence.
More than 140 police were deployed to scour the areas between western Switzerland's Morges and St Prex, after a new witness came forward.
Eleven dogs from Austria, France and Switzerland also took part in the two-day operation which ended on Friday evening.
"Despite the large-scale search undertaken by canton Vaud police and partners, the search, which ended at 4 pm, did not provide any new material for the investigation, which is continuing in France and in Italy, as well as in Switzerland," police said in a statement.
No trace has so far been found of six-year-old Livia and Alessia Schepp since they disappeared at the end of January along with their father Matthias.
He later threw himself under a train in southern Italy after having sent a letter to his estranged Italian-born wife in which he told her he had killed the fair-haired girls and that they were "resting in peace in a quiet area."
The latest search in Switzerland was launched after a witness came forward last week to give testimony about a man who was seen carrying a suitcase in the Boiron region -- near western Switzerland's Morges.
Even though there was no breakthrough, the mother of the twins, Irina Lucidi, told journalists on Friday evening that she remained hopeful. "Hope is the last thing to die," she said.