Mohammed Junaid Babar, 35, confessed in 2004 to setting up the camp in South Waziristan, Pakistan, and equipping it with explosives, night vision goggles and camping gear. He told a federal judge in New York that he knew some of the militants were planning a bomb attack in Britain.
A year after his confession, four men who were trained at the camp detonated backpack bombs in the London subway, killing themselves and 52 victims. After the bombings, Babar testified for the government in four trials targeting al-Qaida militants, three of the trials in Britain and one in Canada. At least 10 people were convicted because of his testimony, the U.S. government says.
Babar pleaded guilty to five terrorism charges and faced a possible 70 years in prison, but court documents show that on Dec. 10 he was sentenced to time served and 10 years of probation as a reward for his cooperation. In all, he spent only four years and eight months behind bars, the U.S. Attorney's Office said.
His sentence, which was originally reported on Monday by the Guardian newspaper, prompted a fierce reaction in Britain. A lawyer representing victims' families and survivors of the London bombings called the move "crazy."
"There is no way a reduction of this size has any regard to the feelings of victims," Clifford Tibber said Monday.
Graham Foulkes, whose 22-year-old son David was killed by one of the blasts that hit London's transport network, said Babar's cooperation with U.S. authorities does not diminish his role in the attacks.
"To be responsible for the deaths of 52 people, serve four-and-a-half years and be released and to say that means he has paid his debt to society just beggars belief," Foulkes told the U.K.'s Guardian newspaper.
Babar's defense lawyer did not immediately return a telephone call seeking comment.
Babar, a U.S. citizen, was arrested in 2004 on five charges of supporting al-Qaida. In a court appearance in June 2004, he told federal judge Victor Marrero that he helped set up the base in the summer of 2003 to train Taliban militants who were fighting U.S. troops in Afghanistan.
He said he delivered night vision goggles, sleeping bags, waterproof socks, rain ponchos and money to a "high ranking official" of al-Qaida who was running the camp. He also arranged shipments of aluminum nitrate, ammonium nitrate and aluminum powder for making bombs that were tested at the camp.
"I was aware that some of the people who attended the jihad training camp had ideas about, you know, plotting against some targets in the United Kingdom, and I provided some of the materials," Babar told the judge.
During testimony he gave in the Canadian and British trials, Babar said he became radicalized by the U.S. invasion of Afghanistan in 2001. He quit his job as a computer programmer in New York and moved to Lahore, Pakistan. There he participated in two failed plots to kill then-President Pervez Musharraf and became familiar with other Al-Qaida recruits from abroad.
As part of his Dec. 10 sentencing, the judge ordered Babar to pay a $500 fine. Prosecutors agreed to enroll him in the U.S. government's witness protection program and give new identities to him and his family. Babar's plea agreement with the government bars him from striking any book deals or giving interviews to news media.
Under the terms of his release Babar must meet monthly with a probation officer and cannot travel without the government's permission. After five years he can apply to have the remaining five years of probation lifted, court documents show.
On Monday the U.S. Attorney's office originally said Babar had been jailed for five years. It later issued a correction, saying he only spent 56 months behind bars.