WATCH: US envoy says 'shared intelligence from Five Eyes partners' behind Trudeau's India allegation

• Trudeau accused India of killing Hardeep Singh Nijjar
• Five Eyes provided information to Trudeau, says Cohen
• Indian authorities deny allegations of killing Nijjar

David Cohen, the United States Ambassador to Canada, informed that a "shared intelligence among Five Eyes partners" provided Prime Minister Justin Trudeau with information about the connection between the death of Sikh leader Hardeep Singh Nijjar and the Indian government.

This week's international crisis between India and Canada was brought on by the passing of a Khalistani Sikh leader.

In a statement made on Monday, PM Trudeau asserted that there were "credible reasons to think that operatives of the government of India were involved" in the murder of Hardeep Singh Nijjar.

According to Cohen, Trudeau's claim was made following information provided by "shared intelligence among Five Eyes partners."

“There was shared intelligence among Five Eyes partners that helped lead Canada to make the statements that the Prime Minister made. In the days since, as diplomatic tensions continue to ratchet up — from Canada reassessing its staffing in India, to India suspending visa services for Canadians — there have been swirling questions about what intelligence is at the centre of this story, who was aware of it, and when," the US Ambassador to Canada told CTV News Channel.

The US, UK, Australia, Canada, and New Zealand are members of the intelligence alliance known as Five Eyes which includes both surveillance-based and signal intelligence.

This is the first confirmation of collaboration between Canada and the Five Eyes allies by a US government official.

A Canada-India diplomatic crisis started when Trudeau accused Indian government officials in the June murder of Sikh leader Hardeep Singh Nijjar. 

On June 18, a Canadian citizen named Nijjar was murdered in Surrey, British Columbia. 

However, in India, he was a wanted terrorist.

The Indian government was urged earlier on Friday by the US to collaborate with Canada in the investigation of Nijjar's murder.

“We have been consulting throughout very closely with our Canadian colleagues – and not just consulting, coordinating with them – on this issue. And from our perspective, it is critical that the Canadian investigation proceed, and it would be important that India work with the Canadians on this investigation. We want to see accountability, and it’s important that the investigation run its course and lead to that result," Antony Blinken said.