It was clear early on Thursday that Justin Trudeau's Indian agenda had been derailed.

While posing for a photo at a mosque in Old Delhi, an Indian television reporter shouted to the Canadian prime minister, "Mister Trudeau … why did you invite a Khalistani terrorist for a reception?"

It got worse from there.

The Canadian media had held off shouting at the prime minister at the mosque because it was a place of worship. But that detente ended at a later photo-op when the prime minister visited a school to play cricket.

As Trudeau strode across the cricket pitch with his children, he barely came within a football field of the media, who repeatedly shouted questions about how Jaspal Atwal could have ended up on a Canadian guest list.

Shouting questions across a cricket pitch is not how things normally play out on an official prime ministerial visit. But it's what happens when the Prime Minister's Office initially says it won't change the schedule to answer questions about an explosive story.

Trudeau on Jaspal Atwal 0:45

It's also what happens when a man convicted of attempted murder — a former member of a Sikh extremist organization banned as a terrorist group — is photographed posing with the prime minister's wife at a private event in Mumbai.

Jailed in Canada for assassination attempt

Atwal was convicted in 1986 of the attempted assassination of an Indian state cabinet minister who was visiting Vancouver Island, and went to prison. But on Tuesday night in Mumbai, he was posing with Sophie Grégoire Trudeau, as well as Canadian cabinet ministers and MPs.

Sophie Grégoire Trudeau and Jaspal Atwal pictured in Mumbai on Tuesday. The Trudeaus attended a business and cultural event in the city that evening in celebratation of Indian cinema. (Name withheld by request)

It emerged Wednesday — thanks to the CBC's Terry Milewski — that Atwal had been formally invited to a Thursday night reception at Canada House, the official residence of the country's high commissioner to India. That invitation was swiftly rescinded once the CBC broke the news to the PMO.

Perhaps the most frustrating part of this controversy for the Canadian delegation is that it was self-inflicted. CBC News reported that Atwal was invited to the reception at the request of Liberal MP Randeep Sarai, one of 14 MPs who paid their own way to take part in Trudeau's official visit.

Liberal MP Randeep Sarai, in the white turban, is one of 14 MPs who paid their own way to take part in Trudeau's official visit to India. CBC News reported Sarai invited Jaspal Atwal to a reception in New Delhi on Thursday. (Pool photo)

Sarai later issued a statement confirming that report: "This person should never have been invited in the first place," he said. "I alone facilitated this request to attend this important event. I should have exercised better judgment, and I take full responsibility for my actions."

But a statement from a largely unknown backbencher isn't quite enough when a controversy sideswipes an international trip. The prime minister eventually changed the daily schedule and gave a brief statement before giving a speech to a business group. He did not take any questions.

"Obviously we take this situation extremely seriously," Trudeau said. "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."

Security questions

It seems impossible to believe that Sarai — a Sikh who represents the B.C. riding of Surrey Centre — would not have known about Atwal's past. Sarai was visible at official events earlier in the week, but has not been seen since this news broke.

'It's a screening failure, it's a security failure, it's a political failure,' says the former B.C. premier of the invitation to convicted attempted murderer Jaspal Atwal to an event with the Prime Minister. 6:58

But even knowing the origin of the invitation fails to answer other key questions. The PMO won't explain how Atwal could have been missed in the vetting and security checks of guests invited to private events with Trudeau, offering instead a blanket statement: "We don't talk about the PM's security."

There are also unanswered questions about how a man convicted of trying to murder an Indian politician could even get a visa to enter this country. Indian officials say they are looking into it.

It felt great to hear Canadian Prime Minister <a href="https://twitter.com/JustinTrudeau?ref_src=twsrc%5Etfw">@JustinTrudeau</a> appreciate the progress made by Punjab under the <a href="https://twitter.com/INCPunjab?ref_src=twsrc%5Etfw">@INCPunjab</a> government. Thank you Mr Trudeau for your kind words. I sincerely value your opinion and look forward to your support in taking the state’s progress forward. —@capt_amarinder

The news is bad for Trudeau. The timing makes it even worse.

It broke just hours after the prime minister had successfully defused an ongoing controversy about whether his government is sympathetic to Sikh separatist extremism.

Trudeau and Defence Minister Harjitt Sajjan met Wednesday with Amarinder Singh, the chief minister of Punjab. Singh famously snubbed Sajjan during a visit to India last year. He also had accused Trudeau of allowing Sikh extremists to infiltrate his cabinet.

Those claims had overshadowed the early days of this trip. But after the meeting, Singh praised Trudeau's support for a united India. It appeared as if the Sikh separatism story had been put to bed.

Well, Canada had better hope that Singh isn't a big consumer of news, because the Atwal story is generating headlines across India that will make the Canadian government squirm. Headline after screaming headline reports that a "Khalistani terrorist" had been invited to an event with Trudeau.

Indian television is running the photos of Atwal with Trudeau's wife. One anchor on NDTV — one of the country's largest and more credible news channels — called it a "big embarrassment for the visiting Canadian prime minister."

Trudeau stops to speak to media as he arrives to the India Canada Business Session in New Delhi on Thursday. (Sean Kilpatrick/Canadian Press)

It's the dominant story just one day before Trudeau is set to meet with Indian Prime Minister Narendra Modi — the main event of a trip with the stated goal of deepening ties between the two countries.

Now Trudeau will have to explain to the leader of the world's largest democracy why a Canadian member of Parliament invited the would-be assassin of an Indian politician to a party with the prime minister.

'I can't think of a single foreign policy analyst who would think a costume parade masquerading as foreign policy is actually a way to exercise our national interests,' says the former policy director to John Baird. 6:44