A senior government official with knowledge of the prime minister's security protocols is suggesting rogue political elements in India may have orchestrated the embarrassing invitation of a would-be political assassin to a formal dinner with Justin Trudeau in an attempt to make the Canadian government appear sympathetic to Sikh extremism.

The official said questions should be asked of the Indian government about how Jaspal Atwal, convicted in the attempted murder of a Indian cabinet minister visiting Canada in 1986, was taken off a blacklist of people banned by India from entering the country — and then suddenly surfaced during Trudeau's visit there this week.

Atwal received his invitation through B.C. Liberal MP Randeep Sarai, who put the former member of a banned extremist group on the guest list for a dinner at the Canadian High Commission in India.

The source said the expectation is that MPs who put names on the guest list should be able to vouch for that guest — and in this case, Sarai realizes that he should not have added Atwal's name and has taken responsibility for his actions.

Sarai issued a statement Thursday echoing that sentiment and apologizing for distracting attention away from Trudeau's official visit.

"Let me be clear — this person should never have been invited in the first place," the statement said. "I alone facilitated his request to attend this important event. I should have exercised better judgment, and I take full responsibility for my actions."

Atwal was also pictured an an earlier event in Mumbai posing with Sophie Trudeau and Liberal MPs, including Minister of Infrastructure and Communities Amarjeet Sohi.

Atwal's travel permissions

An official spokesperson for the Indian government had no explanation for how Atwal managed to get his name removed from the list of people banned from travelling to the country, or any information to offer on the documents he used to get into India.

"It is something which I cannot say immediately how that happened," said Shri Raveesh Kumar. "There are different ways of people coming into India. Whether you are an Indian national, whether you hold OCI card, so we are ascertaining details from our mission.

"We will have to see how this happened and then I can perhaps at a later stage share details on this matter."

Sophie Trudeau and Jaspal Atwal pictured at a film industry influencers event with Indian film stars in Mumbai Feb. 20. (Name withheld by request)

A senior government official told CBC News that not all guests attending events with the prime minister are vetted for potential security risks because the large number of people attending such events, and the constantly changing list of attendees, make that task very difficult.

Instead, the source said, a risk-based approach is used to assess potential threats to the prime minister at events such as town halls or formal dinners; on the ground, security is managed by Trudeau's RCMP security detail. The official also said there are no plans to change the way security is managed in light of the breach.

Trudeau has been on the back foot since CBC News revealed that Atwall received an invitation to the Canadian High Commission dinner in India, where the Trudeaus were in attendance.

Atwall was a member of the International Sikh Youth Federation, banned as a terrorist group in Canada, the U.K., the U.S. and India. He was convicted of the attempted murder of an Indian cabinet minister, Malkiat Singh Sidhu, on Vancouver Island in 1986.

He's also been convicted in an automobile fraud case and was charged, but not convicted, in a 1985 near-fatal attack on Ujjal Dosanjh, an opponent of the Sikh separatist movement who later became premier of British Columbia.

Trudeau responds

"Obviously we take this situation extremely seriously," Trudeau said in India Thursday. "The individual in question never should have received an invitation and, as soon as we found out, we rescinded the invitation immediately.

"The member of Parliament who included this individual has, and will, assume full responsibility for his actions."

The Indian government, for its part, has not been publicly critical of the Trudeau government over the security breach.

"I think this is something which should be addressed to the Canadian side and I believe they have already clarified," said Shri Raveesh Kumar Thursday. "They have said that it was an oversight and that is the reason the invitation for the reception ... has been withdrawn."