WASHINGTON, United States — A controversy over Chinese e-commerce giant Alibaba's admittance into a respected Washington-based anti-counterfeiting coalition intensified Wednesday when board members received an anonymous email threatening a mass defection unless Alibaba is pushed out, according to a copy obtained by The Associated Press.

The letter to board members of the International Anti-Counterfeiting Coalition outlined a list of concerns, including Alibaba's membership and ties between the coalition's president, Robert Barchiesi, and Matthew Bassiur, who took over as Alibaba's head of intellectual property enforcement in December.

"The majority will not continue on as IACC members if you continue to allow membership to Alibaba," said the email, which was unsigned but contained many accurate details about the group's inner workings. "New governance and complete transparency is needed for this organisation to resurrect itself."

Luxury fashion brands Gucci America and Michael Kors have already quit the lobbying group since the April announcement of the board's decision to admit Alibaba, whose e-commerce platforms are widely criticised for selling counterfeit merchandise. Michael Kors' general counsel said in a letter explaining the company's decision to pull out that IACC had "chosen to provide cover to our most dangerous and damaging adversary."

The protest email contended that additional unnamed members of the coalition would pull out unless changes were made. Former IACC board member Deborah Greaves, a partner at a law firm that belongs to the anti-counterfeiting group, said the letter "is arguing sentiments shared by a lot of people." The AP was unable to determine who sent the letter, which circulated widely among IACC's members.

The anti-counterfeiting group said its board has full confidence in its president.

By Erika Kinetz and Desmond Butler.