The father of an 11-year-old girl has been charged with murder for sending her on a 10-mile trek in below-freezing temperatures on Christmas Day after his car became stuck in a snowdrift.

Robert Aragon, 55, of Jerome, Idaho, had been taking his daughter, Sage, and her brother, Bear, 12, to visit their mother 30 miles away. When his car came to a halt near Shoshone, he is alleged to have let the children out to walk the rest of the way.

The two children had to trudge through deep snow. Sage was not dressed for the conditions: she had a down coat and snow boots but only pyjama bottoms.

According to the police and their mother, JoLeta Jenks, Bear said the two split up after a few miles when his sister argued in favour of abandoning the attempt to reach their mother's and to retrace their steps to the car.

"[Bear] kept on telling her: 'Let's go, Sage, let's go, Sage'," Jenks said. "She said: 'No, I'm going back'."

Police were alerted after Jenks phoned Aragon to ask why the children had not turned up. After freeing his car, Aragon had returned to Jerome with his cousin, Kenneth Quintana, who had been a passenger.

After hearing from Jenks that the children had not turned up, the police said Aragon and Quintana drove back to look for them, but without success.

The police called in all available officers to join a search and sent out a snowplough and snowmobiles.

They found Bear at a rest area on the highway at about 10pm, about four miles from where he had left the car. He was wearing only his underwear, having thrown away his jacket, trousers and shoes, a not uncommon reaction by people suffering from hypothermia.

Sage was found, her body mostly covered by snow, about three miles from where they had left the car. The coroner's office said her condition was consistent with death from hypothermia.

Quintana, quoted on the website SunValleyOnline, defended Aragon: "He didn't send those kids out there to die. He just wanted their mother to spend Christmas with them.

"We thought their mother was going to meet up with the children. Where was she? How were we supposed to know she wasn't coming?"

But Jenks said: "They didn't even call me, telling me they were walking." She added there was no possibility of her picking up the children as she has no car.

Aragon banged his forehead repeatedly on the defendant's table when the charges, including second-degree murder, were read out yesterday.

When told that the charges could mean life in prison, Aragon shouted: "Oh, my God."

Bail was set at $500,000 (£347,000). Aragon was unable to find the money and remains in jail. He is due to return to court on 7 January.

Jenks said she did not understand why Aragon let the children walk, but added: "I don't need to sit and yell. I know he's going through hell right now."