Nur Mohamed points out his missing niece, Rupchanda, in a family photo. © UNICEF/UN0226426/BROWN

A young girl in a turquoise skirt stares out from a faded colour photograph. Holding a small child in her arms, she stands among a group of adults and children posing in what appears to be a family portrait.

According to Nur Mohamed, a Rohingya refugee living in Hakimpara camp, the girl pictured in the front row is his niece, Rupchanda Begum, then 10 years old.

“She was a pretty girl, and intelligent too,” says Mohamed. “She never got in trouble.”

Listening to the conversation are Rupchanda's two younger brothers, Yasin, 9 and Ali, 7. The two boys were the last to see Rupchanda before she vanished one day last September.

The three siblings were living with an aunt in Kutupalong camp at the time. They had come to Bangladesh only weeks earlier as orphans, after their parents and four brothers and sisters were killed during the wave of violence that swept their home state of Rakhine.

That morning, the three children had gone to join refugees waiting in line for snacks distributed by an NGO.

“It was very crowded. People were pushing each other,” recalled Yasin. Suddenly, their sister was nowhere to be seen. “We were crying – we had no idea where she had gone.”

Public announcements were put out on loudspeakers, but to no avail. Rupchanda had disappeared.

“I think someone took her,” says Mohamed's wife, Rahiema. The couple now look after Yasin and Ali in addition to their own six children.

“It is difficult to look after so many,” he says. “But what else can we do?”