India, Sept. 5 -- When Amrit Diyali saw a human hand washed downstream by floodwaters, he was struck by how closely it resembled his younger brother Raj Kumar's.

Raj Kumar, 33, has been missing along with his wife Shriti, 30, and their four-year-old son Siraj since devastating floods struck Nepal on August 26.

"I found a hand that looks exactly like uncle's," Diyali's nephew Avinash told him after sending him a photograph of the severed hand, according to The Kathmandu Post.

For Diyali's family, the discovery brought both hope and dread. A DNA test is now their only chance of knowing whether the remains belong to Raj Kumar.

Their ordeal reflects a much larger challenge facing Nepal, where authorities are relying on DNA testing to iden...