A media report says that US intelligence officials were aware of plans to attack Mumbai years before the terrorist incident killed more than 170 people in India's main port city in 2008.
A report published by the Washington Post on Wednesday said that the Federal Bureau of Investigation (FBI) had been tipped off in 2005 about an American national, who masterminded attacks on the Indian financial hub three years later.
The man identified as David Coleman Headley underwent intensive training with banned militant groups in Pakistan, the report added.
Based on the report, Headley's wife told FBI agents that her husband was in close contact with Lashkar-e-Taiba (LeT), the group blamed by India for the deadly attacks on Mumbai.
The report also says Headley went to Mumbai five times to scout landmark locations and targets for the attack on the city.
The report comes months after the Pakistani interior ministry suggested that the Mumbai attack were planned outside Pakistan.