WASHINGTON — The Campaign Legal Center is complaining in a letter to the White House that a top adviser to President Donald Trump may be illegally accepting outside professional services.

Steve Bannon has worked with publicist Alexandra Preate since he was head of Breitbart News. Preate has continued to work with reporters on Bannon’s behalf even though she is not a government employee. A recent article by the Center for Public Integrity quotes an associate of Preate’s saying she doesn’t receive pay from Bannon.

The Campaign Legal Center says that appears to be a violation of what’s called the Antideficiency Act. The law says government employees “may not accept voluntary services for (the) government or employ personal services exceeding that authorized by law.”

The White House and Preate did not immediately comment.

In a letter to new White House chief of staff John Kelly, Attorney General Jeff Sessions and the Office of Government Ethics, the Campaign Legal Center seeks an investigation of the situation and notes that violations of the Antideficiency Act can be punished with fines and prison time.

“This particular situation appears to be unprecedented,” said Brendan Fischer, director for federal reform at the Campaign Legal Center. “The concern here is that there may be some secret set of donors who have interests before the government, who are paying for government services.”

The Campaign Legal Center is a Washington-based nonprofit that recently hired Walter Shaub, the former Office of Government Ethics director who has been intensely critical of the Trump administration’s handling of conflict of interest rules.

The reporter referenced in the complaint letter says that Preate spoke with her 18 times off the record when she was inquiring about Bannon’s personal financial disclosure, a document he filed with the government. The reporter says she contacted the White House press office and then heard from Preate, who in addition to speaking with her also put her in touch with a White House lawyer.