The National Investigation Agency has formed several teams in Mumbai as well as in other states to probe LeT operative David Headley, and his accomplice Tahawwar Hussain Rana trail in India . The two men were arrested in Chicago last month for plotting terror strikes in and outside the US places in India. New leads suggest Rana had visited Kochi before 26/11 attack. The NIA officials who arrived in Mumbai yesterday will examine the CCTV footages, from various hotels of the metropolis where the duo had visited. The NIA sleuths are also said to have questioned film maker Mahesh Bhatt's son Rahul and three other people including the gym proprietor where Headley is believed to have met Rahul.The Home Secretary G K Pillai when made it clear that no one has been given clean chit in the Headley case so far and the investigation is still on .He said this in reply to a question on whether a clean chit has been given to Rahul. Speaking to media on the sidelines of a function in New Delhi, Mr. Pillai said that Tahawur Hassan Rana had visited Kochi in Kerala and investigations are on to find out about his activities in the city. Rana had visited Kochi last year 10 days before the terror attacks in Mumbai. Mr Pillai said that it will take four to six weeks to complete investigations into the duo's trail in India. He said, the national investigation agency is trying to find out if the two had played any role in the Mumbai terror attack last year or the serial blast between 2006 to 2008.<br/><br/>Meanwhile, searches were carried out in cyber cafes and hotels in Central Delhi's Pahar Ganj area in connection with the terror designs of David Headley who is reported to have stayed there in March this year. However, the police is tight lipped about the searches saying that it is a routine exercise. <br/>