The eldest son of Canada's notorious Khadr family is in a Toronto court Monday to fight his extradition to the United States.

Abdullah Khadr is fighting extradition to the U.S. (CBC)The U.S. wants to try Abdullah Khadr on charges that he helped buy weapons for al-Qaeda and plotted to kill Americans in Afghanistan. The 28-year-old Khadr has been behind bars since his arrest in December 2005 following his return to Canada from Pakistan, where he had spent a year in custody.

The Crown told the court Monday that Khadr attended a jihadi training camp where he learned how to fire a machine gun, launch a rocket, and even how to ignite bombs. They also tried to link Khadr to his father, Ahmed Saeed Khadr, who was a close friend of Osama bin Laden and a member of al-Qaeda.

But Khadr said that he was just 13 when he was sent to the jihadi training camp in Afghanistan, and that his father had promised to take him to an amusement park in Pakistan, but sent him and his brother to the training camp instead.

Khadr says he was tortured in Pakistan

The prosecution is relying on statements Khadr gave to Canadian and American authorities while in jail in Pakistan and on his return to Canada.

Court documents show the United States had paid Pakistan a $500,000 bounty to arrest Khadr, despite the likelihood he would be tortured. Parts of the case against Khadr are statements he made while in Pakistani hands.

Khadr claims he was tortured while in Pakistani custody before he came back to Canada in December 2005. His lawyers argue the information was the product of his abuse and can't be relied on.

Khadr's younger brother, Omar, remains in U.S. custody in Guantanamo Bay on charges that he killed an American soldier in Afghanistan in 2002.

with files from The Canadian Press