David Coleman Headley, arrested by the Federal Bureau of Investigation (FBI) for conspiring to carry out terror attacks had visited India, including Mumbai, several times, Home Secretary G K Pillai said on Sunday.

"We do know that Headley had visited India a number of times. That is being investigated," he told reporters in New Delhi when asked about media reports which said that the US citizen had visited the country.

"He has been in Mumbai and some other places," the Home Secretary said to a question about the places Headley had visited in India.

Headley, 49, was arrested on October at Chicago's O'Hare International Airport as he prepared to board a flight to Philadelphia, intending to travel to Pakistan. FBI also arrested Tahawwur Hussain Rana, 48, a Canadian citizen of Pakistani origin, for alleged involvement in terror activities.

While Pillai did not give any further details, sources in the investigating agencies said they were probing Headley's involvement in setting up of an office in Mumbai which used to provide visa and travel facilities to youths.

Mumbai Police has been asked to prepare a list of people using the services of Headley's company to travel abroad.

Some people with whom Headley had got in touch upon his arrival in the country were also being questioned. Sources, however, said so far no arrest or detention has been made.