BEIJING (Reuters) -China has launched an anti-discriminatory investigation against restrictive measures taken by Canada including additional tariffs on Chinese electric vehicles, steel and aluminum products, its commerce ministry said on Thursday.

This type of investigation usually takes three months to complete but could be extended under special circumstances, the ministry said.

Beijing also announced plans this month to probe Canadian canola imports after Ottawa joined the U.S. and the European Union in putting in place tariffs of 100% on Chinese EVs and 25% on Chinese aluminum and steel.

More than half of canola exported by Canada makes its way to China, the world's biggest oilseed importer.

China said it strongly deplored and firmly opposed Canada's "discriminatory unilateral restrictive measures" and it had requested talks with Canada at the World Trade Organization about the tariffs.

Trade friction between the countries heightened this week after Canada said it was "absolutely" considering banning Chinese-made software in EVs, among measures to counter what it calls overcapacity and a security threat.