The Asian Infrastructure Investment Bank "serves China's interest" and Beijing wields "undue" influence over what is supposed to be a multilateral organisation, a former executive told AFP Thursday after resigning.

In the wake of his resignation, Canada's Finance Minister Chrystia Freeland announced Ottawa would "immediately halt all government-led activity at the Bank".

Bob Pickard, the bank's former communications chief, resigned earlier this week and launched a broadside against the institution on his Twitter account.

Speaking to AFP from Tokyo, he doubled down on his allegations that the bank is dominated by members of the Chinese Communist Party (CCP) and primarily funds projects of interest to Beijing.

"It's a resource to the geopolitical goals of the PRC (People's Republic of China)... in practice, I believe it serves China's interest," he said.

"The bank portrays itself as governed by a board of directors and there are a lot of window-dressing foreign executives on the leadership," he said.

But inside the bank, "there's a parallel system, it's adjacent to the public-decision making structure", he added.

In a statement issued after his tweets, AIIB confirmed Pickard's resignation and called his allegations "baseless and disappointing".

The AIIB, a brainchild of Chinese President Xi Jinping, was launched in 2016 to counter Western dominance of the World Bank and the International Monetary Fund.

The United States is not one of its 106 global members, however, having chosen to stay out from the start on concerns over transparency and governance.

Pickard said he was warned after joining the bank around a year ago "not to mess with any of the party people... don't mess with them because they're powerful".

He declined to say who had issued him the warning, but said he raised concerns about the role of party members and their influence a month ago, in writing.

"I also said what I would do... so this can't come as any surprise," he added.

"The response was: 'Don't go there' basically."

Freeland, the Canadian finance minister, said the government would now conduct an "immediate review of the allegations raised and Canada's involvement in the AIIB".

Pickard said he was "happy that my country's government is taking seriously the issue of lack of transparency and undue CCP influence over what is supposed to be a multilateral organisation".

"I believe that the Canadian government will find that ultimately, the interests of this bank do not coincide with the interest of our country.

"Why is Canada participating in an organisation that at the end of the day, makes China more powerful?"

AFP