Khalistani terrorist Jaspal Atwal and sympathiser MP of Canada Amarjit Sohi

Government is trying to figure how Jaspal Atwal was allowed entry into India. Atwal was convicted for trying to kill Punjab Minister in Canada in 1986. He was also invited to Mr Trudeau's official events in Mumbai and Delhi

The presence of Jaspal Atwal, a convicted pro-Khalistan terrorist, at an official event hosted for Canadian Prime Minister Justin Trudeau, has prompted the Indian government also to make inquiries to figure how the separatist leader was allowed back into the country without any red-flags being raised.

"We will have to see how this happened," Raveesh Kumar, the foreign ministry spokesman said on Thursday.

"I cannot immediately say how that happened. There are different ways of people coming into India, whether you are an Indian national, or OCI (Overseas Citizen of India) card holder. We are ascertaining details from our mission," Mr Kumar said.

But the answer might lie at the Home Ministry back in Delhi that maintains a list of pro-Khalistan separatist elements who should not be allowed into the country. Foreign missions run visa requests through this database and rejects requests from people in this negative list.

There were suggestions that the security establishment was also checking if Jaspal Atwal had ever made it to its list and when his name was removed.

Jaspal Atwal was convicted for trying to kill the then Punjab Minister Malkiat Singh Sidhu in Canada in 1986, and was sentenced to 20 years.

It turned out that Jaspal Atwal was also invited to an official dinner in Delhi tonight. The invites were seen to reinforce Canada government's insensitivity in recognising the threats that Khalistani separatists have posed in India.

Within hours, PM Trudeau went public with his disapproval of Jaspal Atwal's presence and Randeep Surai, the Canadian parliamentarian who had invited Atwal, regretted his decision.