Remains believed to be those of a former soldier suspected of kidnapping and murdering his three daughters have been found in a remote wooded area of Washington state, authorities have said.

"While positive identification has not yet been confirmed, preliminary findings suggest the remains belong to Travis Decker," Chelan County Sheriff's Office said in a statement on Thursday.

Decker, 32, had been wanted since 2 June when an officer found his truck and the bodies of his three daughters - nine-year-old Paityn Decker, eight-year-old Evelyn Decker and five-year-old Olivia Decker - at a campsite outside Leavenworth.

They had been bound with zip ties and had plastic bags placed over their heads. A preliminary examination found they died of asphyxiation.

Three days earlier, Decker had faile

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