Bob Pickard, a Canadian national and former global communications chief for the AIIB, announced his resignation in a scathing social media post on Wednesday.
The AIIB earlier on Wednesday said it had accepted Pickard's resignation and called his comments "baseless and disappointing.
China's foreign ministry and Canada's embassy in China did not immediately respond to requests for comment.
China is an important member of the AIIB and has always followed multilateral rules and procedures, the embassy said.
The clash marks a new dip in bilateral relations between Canada and China, which have been frosty for the last five years.
Persons:
Bob Pickard, Xi Jinping, AIIB, Pickard, I've, Michaels, Chrystia Freedland, Laurie Chen, John Geddie
Organizations:
Infrastructure Investment Bank, Chinese Communist Party, Canadian, World Bank, Reuters, Communist, Party, Canadian Finance, Ottawa, Beijing, Thomson
Locations:
BEIJING, Beijing, Ottawa, Canada, Japan, China, China's, Canadian, Shanghai, Toronto, Lincoln