Pakistan-born Chicago businessman Tahawwur Hussain Rana knew well in advance about the deadly Mumbai terror attacks, blamed on Pakistan based Lashkar-e-Taiba (LeT) and offered congratulations to the killers, according to fresh evidence filed by the FBI.

In papers filed in federal court in Chicago on Monday, prosecutors said Rana, who was arrested last month along with another Pakistani-American terror suspect David Headley, learned an attack was about to happen while travelling in Dubai days before the November 26, 2008 attack on India's financial hub.