A Sino-Canadian row reared its head on Monday after one of two Canadians jailed by China for nearly three years claimed he was unwittingly used for intelligence gathering and is seeking compensation from Ottawa.

Beijing's 2018 to 2021 detentions of Canadians Michael Spavor and Michael Kovrig had plunged bilateral relations into a deep freeze.

Spavor reportedly now blames Kovrig, with whom he had provided information on North Korea, unaware that it would be shared with Canada and its intelligence partners, for their incarceration.

And, he is seeking millions of dollars in compensation from Ottawa, according to the Globe and Mail newspaper.

"The allegations are unfounded," Kovrig told AFP.

Spavor's lawyer declined to comment while Canada's foreign ministry referred to Prime Minister Justin Trudeau's 2021 remarks also calling the espionage charges "unfounded."

China's embassy in Ottawa, however, said in a statement that Spavor's claim "fully exposes Canada's hypocrisy."

"Canada's hyping up of so-called 'arbitrary detention' by China is purely a thief crying 'stop thief,'" it said.

At the time of their detention, Ottawa rejected the spying charges leveled against the two Michaels, accusing Beijing of having arbitrarily detained them in retaliation for its arrest on a US warrant of Meng Wanzhou, a Huawei senior executive and the daughter of its founder, in December 2018.

All three were released in September 2021.

On Monday Ottawa maintained both men's innocence, saying in a statement: "Perpetuating the notion that either Michael was involved in espionage is only perpetuating a false narrative under which they were detained by China."

Spavor lived in China near the North Korean border and was among only a handful of Westerners who has met North Korean leader Kim Jong Un.

He ran a tourist travel business, helping arrange visits including by former basketball star Dennis Rodman to the isolated country.

Kovrig served as a diplomat in Beijing from 2012 to 2014, and would have in the course of his duties collected information on security and stability issues in China.

Ottawa does not be consider this to be covert intelligence work.

Kovrig was on leave from his diplomat job and working for a Hong Kong nonprofit organization when he was arrested in China.

Relations between Ottawa and Beijing have remained frosty, with fresh accusations that Beijing attempted to intimidate Canadian MPs leading to the expulsion of a Chinese diplomat in May.

A public inquiry has also been launched into alleged Chinese meddling in Canadian elections -- accusations that Beijing has called "groundless."