Atheists and nonbelievers from across the country will muster on Capitol Hill next week for a summit meeting organized by the Secular Coalition for America, a growing alliance of groups that has been giving the religious right an intensifying case of heartburn by lobbying for the separation of government and religion.

But what the Secular Coalition has not made public is that last week it dismissed its executive director, Edwina Rogers, an experienced Republican lobbyist whose conservative pedigree elevated the profile of the secular movement when she was hired just over two years ago.

Ms. Rogers said in an interview that she was given no warning and no reason for her termination, but that she suspected she was being blamed for organization funds discovered to be missing and said to be embezzled by two of her subordinates. An internal audit, obtained by The New York Times, found that two employees who handled the Secular Coalition’s finances embezzled $78,805, mostly by using the coalition’s credit cards to pay for restaurant meals, travel and plastic surgery. Ms. Rogers said she had no authority over the finances, but discovered the misuse of funds, reported it to the police, fired the two employees and commissioned the audit with the approval of the board.

The president of the Secular Coalition, Amanda K. Metskas, did not return phone calls, but she confirmed in an email that Ms. Rogers “has never been a suspect in the misdirection of funds at the Secular Coalition for America.” Ms. Metskas would say only that Ms. Rogers had “moved on” for reasons she could not discuss because they were “confidential personnel matters.”