Investigators in the international rescue effort for two missing six-year-old twins say their father had visited websites giving advice on poison.
As the search intensifies on the island of Corsica for Alessia and Livia, the computer of their father, Matthias Schepp, has been examined.
After failing to return the girls to his estranged wife in Switzerland, he committed suicide by throwing himself in front of a train in Italy. The possible link to poison is being seen as a potentially disturbing development.
The twins’ mother has made a televised appeal for information.
Several witnesses saw the twins with their father on a ferry to Corsica. An account, still to be confirmed, saying the girls did later disembark with him, has encouraged their mother’s family.
“Someone has seen Matthias with two children coming off the ferry in Corsica which partially excludes the gruesome assumption of an irreparable act during the journey at sea,” said their uncle, Valerio Lucidi.
But was Corsica the twins final destination? Another unconfirmed report says they were later spotted with their father in Italy.
Investigators are also searching for a tape recorder belonging to Matthias Schepp which could provide information about the twins’ fate.