A U.S. congressional committee that monitors human rights in China has asked the president of the American Bar Association to explain why the ABA’s book publishing unit reversed plans to publish a book by Chinese human rights lawyer Teng Biao.

In a letter on Tuesday, the leaders of the Congressional-Executive Commission on China asked ABA president Paulette Brown and executive director Jack Rives for information to determine whether the ABA canceled the book project in order to protect the ABA’s interests in China.