John Holdren, the US presidential science advisor, hosted a dinner and meetings between US and Chinese science officials, a move that the Government Accountability Office now says violated a ban on certain kinds of collaborative research between the two countries, reports Nature News' Eugenie Samuel Reich. Congressman Frank Wolf (R-Va.), who heads the subcommittee that funds science agencies like Holdren's White House Office of Science and Technology Policy, asked the Department of Justice to step in and curb Holdren's activities with China, Reich says. But Holdren says he has the right to conduct diplomacy on behalf of the president without prior approval from Congress. "Science-policy experts say that the dispute has the potential to cast a cloud over joint academic and commercial research efforts between the two economic superpowers," Reich says. "US agencies now have more than 30 agreements on scientific cooperation with their equivalents in the Chinese government. … Chinese researchers are now more likely to collaborate and co-author papers with scientists from the United States than with those from any other country." Wolf's spokesman says the congressman is concerned about China's spying and possibly stealing technology, particularly "advanced space technologies."