"Of the 272 individuals on the terrorist watch list who attempted to buy firearms in 2010, 247 were allowed to make the purchase after going through required background checks,"the Government Accountability Office (GAO) said today.
The GAO, US Congress' investigative arm, received the new numbers from the FBI.
The numbers released today build on data compiled since 2004, demonstrating the significant threat that the "Terror Gap" in US law poses to the American public, said New Jersey Senator Frank R Lautenberg.
"It defies common sense that people on the terror watch list continue to be cleared to buy weapons legally in the United States," he said, adding, "This is a homeland security issue, not a gun issue, and there's no reason we shouldn't be able to stop a terrorist from buying a dangerous weapon in the United States."
Lautenberg said between February 2004 and December 2010, there were 1,453 cases in which individuals on the terror watch list were involved in a firearm or explosives background check.
In 91 per cent of those cases – a total of 1,321 times – they were cleared to proceed with the purchase.
On three occasions, a known or suspected terrorist was cleared to purchase explosives.
The updated figures provided by GAO include complete statistics for 2010 and build on a report that documented gun and explosive sales to known or suspected terrorists from February 2004 – February 2010.
As such the legislation introduced by Lautenberg would provide the Attorney General with authority to stop the sale of guns or explosives when a background check reveals that the purchaser is a known or suspected terrorist and the Attorney General reasonably believes that the person may use a firearm or explosives in connection with terrorism.
Under current federal law, being a known or suspected terrorist is not a disqualifying factor for buying guns and explosives.