Authorities are searching for six-year-old twin girls after their father died when he threw himself under a train in Italy.
Alessia and Livia Schepp were taken from their home in Switzerland by their father, Matthias, on January 30.
The Herald Sun reported that he sent the girls' mother, who is of Italian origin, a postcard from Marseille a day later, saying he was desperate and could not live without her.
Swiss police said he had withdrawn large sums of money from cash machines in that city.
IGN reported that the body of the 43-year-old Swiss national was found on the tracks near the train station in Cerignola, in the province of Foggia, after he was killed shortly before midnight on February 3.
The ANSA news agency reported that helicopters, sniffer dogs, trained rescue workers and volunteers have all been involved in the search so far.
According to GenevaLunch, police said the girls are trilingual in French, Italian and Swiss-German.
The parents, who worked for a tobacco multinational in Lausanne, separated in August and the woman asked her husband for a divorce about a week ago. The man was reported to be Canadian, as well as Swiss.
A Facebook page has been set up to raise awareness about the missing girls.