CHARLESTON (AP) — More than four months after an investigation shut down her thriving pain clinic, a West Virginia doctor continues to spar with federal prosecutors over her case.

No charges have been filed against the physician, Katherine Hoover, or others who worked at the Mountain Medical Care Center. But the Williamson clinic has remained closed since the late March raid, and authorities are hanging on to at least $436,000 they seized as part of the probe.

On her own, without using a lawyer, Hoover has filed a court motion asking U.S. Magistrate Judge Mary Stanley to throw out at least one of the dozen or so search warrants obtained by investigators in the case. Besides targeting the clinic and the bank accounts, the warrants also allowed authorities to seize patient records and Hoover’s 2007 BMW convertible, and search residences of Hoover and other clinic staff.

‘‘Many patients with severe chronic pain are unable to receive treatment,’’ Hoover said in an e-mail to The Associated Press this week. ‘‘The attack on doctors benefits the government because they seize assets without a trial of any sort.’’

Prosecutors counter that Hoover’s challenge of the warrants lacks merit. They also said in a late June filing that they continue to investigate whether the clinic operated as an illicit ‘‘pill mill.’’

Investigators allege the clinic handed out pain drug prescriptions for cash-only fees of at least $150 per visit. The warrants sought to recoup an estimated $4.6 million from these payments.

The state-federal task force also cited the more than 335,130 prescriptions issued under Hoover’s name between December 2002 and late January 2010 — more than any other West Virginia physician during that time. More than 30,470 people received prescriptions from her last year alone, they allege.

The 59-year-old Hoover, who denies any wrongdoing, has also since lost her license to practice in West Virginia. The state Board of Medicine revoked it in May after she failed to attend a hearing in an unrelated disciplinary action against her.

Hoover has been in the Bahamas, where she says she remains for both health and safety reasons. She alleges that she and her husband were poisoned in July 2008 while they were pursuing a federal lawsuit over the death of their eldest son.

The lawsuit alleged that Michael Tomasic, 26, was fatally beaten at the North Central Regional Jail following a September 2005 misdemeanor arrest. The state settled the lawsuit for $750,000 last year without admitting any fault.

Hoover continues to allege that her son’s death was part of a larger conspiracy, and has invoked these allegations in her U.S. District Court petitions challenging the March raid. One of her filings seeks to remove the federal prosecutors handling the case. Stanley, the U.S. magistrate, has given prosecutors until Aug. 13 to respond.

Late last month, Hoover petitioned for Stanley’s removal from the case because she approved the search and seizure warrant requests. Stanley has not issued an order responding to that filing.