California state senator who advocated gun control legislation asked for campaign donations in exchange for introducing an undercover FBI agent to an arms trafficker and told him how to get shoulder-fired automatic weapons and missiles from a Muslim separatist group in the Philippines, according to court documents unsealed Wednesday.

The allegations against state Sen. Leland Yee were outlined in an FBI affidavit in support of a criminal complaint. The affidavit accuses Yee of conspiracy to deal firearms without a license and to illegally import firearms. He was arrested Wednesday and appeared later in federal court, where bail was set at $500,000, CBS News reports.

Yee discussed helping an undercover agent get weapons worth $500,000 to $2.5 million, including shoulder-fired automatic weapons and missiles, and took him through the entire process of acquiring them from a Muslim separatist group in the Philippines to bringing them to the United States, according to the affidavit by FBI Special Agent Emmanuel V. Pascua.