The American Conservative Union has filed a complaint against Barack ObamaBarack Hussein ObamaTrump takes credit for passing veterans bill that passed under Obama Orlando Sentinel declines to endorse Trump in 2020 Progressive activist: Democratic nominee will 'need to ride a little bit to the center' MORE, seeking to highlight his ties to his former donor Antoin Rezko.

In its complaint to the Senate Ethics Committee, the group says that Obama violated the Senate's gift ban by buying a house from the Rezko's wife. The group alleges that Obama's purchase of another strip of land from Rita Rezko constituted a gift. Obama has said that real estate purchase was "a mistake."

Antoin Rezko has been convicted on fraud and bribery charges. Obama has not been linked to Rezko's case.

Read the ACU's full complaint here.