TORONTO — Burying his face in his hands, a 16-year-old captured in Afghanistan sobs and calls out “Oh Mommy!” in a hidden-camera video released yesterday that provides the first look at interrogations inside the American military prison in Guantanamo Bay.

Lawyers for Toronto-born Omar Khadr released the tapes in hopes of generating sympathy for the young prisoner and to try to persuade the Canadian government to seek custody before he is prosecuted for war crimes at the U.S. special tribunal in Guantanamo later this year.

The son of an alleged Al Qaeda financier, Mr. Khadr is accused of throwing a grenade that killed a U.S. Special Forces soldier during a 2002 firefight in Afghanistan that left another soldier blinded in one eye.

Mr. Khadr, who was 15 at the time, was found in the rubble of a bombed-out compound — badly wounded and near death.

The seven hours of grainy footage, recorded over four days of questioning by Canadian intelligence agents in 2003, shows Mr. Khadr breaking down in tears. At one point he pleads for help and displays chest and back wounds that he says had not healed six months after his capture.

Peeling off his orange prisoner shirt, he shows the wounds and complains he cannot move his arms, saying he has not received proper medical attention, despite requests.

“They look like they’re healing well to me,” the agent says of the injuries.

“No, I’m not. You’re not here [at Guantanamo)],” Mr. Khadr says.

The agent later accuses Mr. Khadr of using his injuries and emotional state to avoid the interrogation.

“No, you don’t care about me,” Mr. Khadr says.

In a 10-minute excerpt released by his Canadian lawyers, Mr. Khadr’s mood swings between calm and relief to rage and grief.

At first, believing that the Canadians were there to help him, Mr. Khadr smiles and repeats several times, “I’m very happy to see you.”

“I’ve been requesting the Canadian government for a very long time,” he says.

By the second day, however, he is seen in a frenzy of despair after realizing the Canadian agents are not there for his release, repeatedly moaning “Ya Umi,” — “Oh Mommy” in Arabic — while left alone in the room.

His lawyers, listening to the same audio, said they believed he was calling out “Help me,” but acknowledged they were unsure. Mr. Khadr’s family, who are from Egypt, said he was calling for his mother, and Arabic-speaking reporters for the Associated Press confirmed that.

Navy Lieutenant Commander William Kuebler, Mr. Khadr’s American military lawyer, said the video shows “a frightened boy” who should be permitted to return to Canada. He said Mr. Khadr was cooperative at the beginning of four days stretch of questioning because, “he believed that if he was cooperative and told them what he thought they wanted to hear that they would take him home.”

On the final day, the agent tells Mr. Khadr that he was “very disappointed” in his behavior, and tries to impress upon him that he should cooperate.

Mr. Khadr says he wants to go back to Canada. “There’s not anything I can do about that,” the agent says.

A Pentagon spokesman, Navy Commander J.D. Gordon, denied that Mr. Khadr was mistreated. “Our policy is to treat detainees humanely and Mr. Khadr has been treated humanely,” Commander Gordon said.

The video was made by American authorities and turned over to Mr. Khadr’s defense team, Gordon said. The tapes are American property.

A Canadian Department of Foreign Affairs report said a Canadian official, Jim Gould, visited Mr. Khadr in 2004 and was told by the American military that the detainee was moved every three hours to different cells.