Omar Khadr will make his final pretrial appearance this week at a U.S. military hearing in Guantanamo Bay, Cuba, before his July trial. (Canadian Press)

Defence lawyers for Canadian Omar Khadr will be seeking to throw out so-called confessions from their client as pretrial hearings begin Wednesday at the U.S. naval prison in Guantanamo Bay, Cuba.

Khadr will make his final pretrial appearance at the hearing, which will determine what evidence the judge and jury of eight military officers can hear at a July trial.

Khadr, 23, is charged with murder, conspiracy and support of terrorism. He is accused of tossing a hand grenade that killed a U.S. medic during a battle in Afghanistan near the Pakistani border in 2002.

Some of the prosecution's key evidence against Khadr is based on confessions Khadr made to military interrogators, including admitting to have thrown the grenade.

Khadr, who was born in Toronto and whose family lives in the Toronto area, also told interrogators that he planted roadside bombs and that his al-Qaeda boss would give him $1,500 cash for every American he killed.

But Khadr's lawyers say those confessions should be thrown out because they were extracted by coercion and torture. They argue that Khadr was lying to the interrogators and said whatever he thought they wanted to hear so they would stop the interrogation.

Along with the confessions, the prosecution also wants to introduce evidence connecting Khadr to al-Qaeda and to show video of the planes crashing into the World Trade Center on Sept. 11, 2001.

The trial is being held under the military commission process, meaning that evidence that would be excluded from a civil trial, including evidence obtained by coercion, can be allowed.

Khadr, 23, has been imprisoned at Guantanamo Bay since he was arrested in Afghanistan at age 15.

The hearing is expected to last two weeks and will include testimony from interrogators who questioned Khadr.