Human remains, believed to be of a man wanted on suspicion of murdering his three daughters, aged nine, eight, and five, have been found in the US state of Washington.

Police had been searching for Travis Decker since officers found his phone and the bodies of his girls Paityn, Evelyn, and Olivia in a remote campground on June 2. His truck was also located nearby.

While positive identification has not yet been confirmed, preliminary findings suggest the remains belong to Travis Decker, stated the Chelan County Sheriff's Office.

The remains were discovered in a remote wooded area south of Leavenworth, Washington, by search teams.

Decker, 32, faced accusations of kidnapping and first-degree murder according to the Wenatchee Police Department. He was suspected of hiding in remote areas of the woods.

The girls' mother reported them missing on May 30, after Decker did not return them home following a visit. They died from apparent suffocation with their wrists bound with zip ties, according to authorities.

Decker's military background included training that may have made him skilled in evasion tactics, with reports suggesting he could survive in the wilderness for extended periods.

The search for him resulted in closures of popular hiking areas, and a $20,000 reward was issued for information leading to his capture.

Officials uncovered Decker's remains on Grindstone Mountain, a short distance from where the girls were found, bringing a tragic chapter of this case closer to a conclusion.