HONG KONG (Reuters) - The Hong Kong government has asked global fast-food chain McDonalds to withdraw a seasoning for its French fries because it could contain a banned artificial sweetener, a spokeswoman said on Sunday. The government said it had discovered that the label for the chain's honey barbecue seasoning mix listed the artificial sweetener stevioside, which is banned in Hong Kong, as an ingredient.

　　The US National Cancer Institute says on its website that the main chemical in stevioside can be converted in a laboratory into a substance that alters genes. Further study is needed to determine whether the sweetener can cause cancer, it says. "We are testing to see if it is a permitted sweetener or not. Legal action would be considered, subject to the results of the test," a spokeswoman for the Hong Kong Food and Environmental Hygiene Department said.

　　McDonalds was not immediately available for comment but newspapers said that the company had since stopped using the powder.