India, April 10 -- Tahawwur Hussain Rana, a key accused in the 26/11 Mumbai terror attack case, had helped co-conspirator David Coleman Headley to obtain an Indian visa, a Mumbai police official familiar with the probe said.

The National Investigation Agency (NIA) on Thursday evening formally arrested Rana following his extradition from the United States.

Rana had served in the Pakistan Army medical corps before emigrating to Canada in late 1990s and started an immigration consultancy firm. He later moved to the US and set up an office in Chicago.

Through his firm, Rana gave cover to Headley to carry out reconnaissance mission in Mumbai prior to the November 2008 attacks and helped him get a ten-year visa extension, the police officia...