The Department of Justice has opened a federal investigation into Sen. Ruben Gallego (D-AZ) related to spending by his Senate campaign, according to reports published Sunday. The investigation represents one of the more prominent federal inquiries into a sitting U.S. senator's campaign finances in recent years.

Gallego, who won Arizona's Senate seat in November 2024 after defeating independent candidate Kyrsten Sinema in the Democratic primary, has not been charged with any crime. Federal investigations into campaign finance matters can take many months or years and do not always result in prosecution.

The scope and precise allegations underlying the DOJ inquiry have not been publicly detailed. Federal campaign finance investigations typically examine whether campaign funds were used for personal expenses, whether contributions were properly disclosed, or whether spending was accurately reported to the Federal Election Commission.

The investigation emerges amid a broader political environment in which the Trump administration has faced accusations from Democrats of weaponizing the Justice Department against political opponents. Gallego has been among the more prominent Democratic voices in the Senate since taking office, making the timing of the investigation a point of contention between the two parties.

Neither Gallego's office nor the DOJ has issued a detailed public statement confirming the full parameters of the probe. The senator has not publicly commented extensively on the investigation as of the time of reporting.