The Federal Election Commission (FEC) fined a pro-Jeb Bush super PAC and a Chinese-owned corporation $940,000 for making illegal contributions to the political group Wednesday.

The FEC fined the pro-Bush PAC, Right to Rise, $390,000 after it was found to have accepted money from a foreign nation, a violation of federal election law. The FEC also fined $550,000 fine to American Pacific International Capital, Inc, the company which contributed $1.3 million to the pro-Bush PAC in 2015.

“Today’s action is a rare and remarkable step by the FEC, and a reminder that safeguarding our elections against foreign interference is in America’s vital national security interests,” Trevor Potter, head of the Campaign Legal Center, said in a statement. “This illegal $1.3 million contribution is unmistakable proof that Citizens United opened the floodgates to foreign money in the U.S., and it is surely the tip of the iceberg.”

Campaign Legal Center, the non-profit which filed the complaint, said the fine was the third largest in FEC history.

American Pacific International Capital donated $1 million to the pro-Jeb Bush PAC in March and $300,000 in June.

According to the FEC, Jeb Bush’s brother, Neil, a board member of American Pacific International Capital, held discussions with fellow APIC board member Gordan Tang about a possible donation. Tang is a Chinese national.

Under federal law, foreign nations are barred from making contributions in U.S. elections, and a foreign national cannot “direct, dictate, control, or directly or indirectly participate in” for spending money for political purposes.