India has constituted a high-level inquiry committee to probe allegations relating to a conspiracy to kill a Sikh extremist on American soil.

The Financial Times, citing unnamed sources, last week reported that US authorities thwarted a plot to assassinate Gurpatwant Singh Pannun, and issued a warning to the Indian government over concerns it was involved in the plot.

External Affairs Ministry Spokesperson Arindam Bagchi said on Wednesday that India constituted a high-level inquiry committee on November 18 to look into all the relevant aspects of the matter.

Pannun, a Sikh extremist and known to be an American and Canadian citizen, is wanted by Indian probe agencies on various terror charges.

"We have already said that during the course of discussions with the US on bilateral security cooperation, the US side shared some inputs pertaining to nexus between organised criminals, gun runners, terrorists and others," Bagchi said.

"We had also indicated that India takes such inputs seriously since they impinge on our national security interests as well, and relevant departments were already examining the issue," he said.

"In this context, it is informed that on November 18, the Government of India constituted a high-level Enquiry Committee to look into all the relevant aspects of the matter," he added.

Bagchi said India will take necessary follow-up action based on the findings of the committee.

The FT report came weeks after Canadian Prime Minister Justin Trudeau made allegations of a "potential" involvement of Indian agents in the killing of Khalistani separatist Hardeep Singh Nijjar in a Vancouver suburb in June.

Following the report, Bagchi on November 22 said the US side shared some inputs pertaining to nexus between organised criminals, gun runners, terrorists and others.

He said the inputs are a "cause of concern" for both countries and they decided to take necessary follow up action.