The U.S District Court in Manhattan received documents from families of the September 11, 2001 victims accusing Iran and Hezbollah in helping al Qaeda carry out the attack.
According to the documents, Iran and Hezbollah did have prior knowledge of the 9/11 attack plans.
This issue was already investigated by the 9/11 Commission and a report was released in 2004 stating there is strong evidence that Iran and Hezbollah helped terrorists come to the US, but the state body was not able to find any proof they were aware of the planned attack.
According to the attorney representing the families, Thomas Mellon, the court documents were gathered from US and Iranian intelligence officials.
This legal process aims to prove that Iran was involved in coordinating attack and knew about the plan, said Mellon.