Police hunt missing six-year-old Swiss twins
Matthias Schepp had snatched Alessia and Livia from the Swiss home of his wife, from whom he was separated, on 30 January.
According to BBC News, he then travelled to France and then Italy, where he threw himself under a train on Friday.
Helicopters, trackers dogs and scores of volunteers are helping the search.
Canadian-born Mr Schepp had sent his estranged wife a letter from Marseille in France, saying he was desperate and could not live without her, Italy's Ansa news agency reports.
The agency quoted Swiss police as saying he had withdrawn large amounts of money from cashpoints in the city.
His body was found on the tracks near the Cerignola Campagna in Italy's Puglia region on Friday - his car was found nearby.
Investigators said they did not know whether Mr Schepp had taken his daughters with him to France and Italy.
An extensive search is underway in Puglia involving French, Italian and Swiss police.
Rescue workers are investigating wells and water tanks as well as searching the area by air.
On Saturday, residents of St Sulpice, from where the girls were taken, staged a walk around the town in a show of support.
To read more see www.bbc.co.uk .