A podiatrist who has a history of professional disciplinary action and has been sued seven times for malpractice since 1997 had his license revoked recently, according to an order made public by the Minnesota Board of Podiatric Medicine Thursday.

Starting in 2006, Robert S. Mullin, of Minnetonka, used incorrect coding to bill Medica and Healthpartners for more than two hundred procedures not normally covered by the providers. When confronted, Mullin failed to repay more than $93,000 it had wrongly collected from the providers.

When the providers began offsetting their losses by refusing to reimburse future claims by Mullin, the podiatrist sent out 470 "demand letters" to patients, claiming they were liable for paying him in lieu of their providers, the order said. The letter made false statements and roughly 250 of the patients had never even had the procedure done, according to the board.

In May, 2011 the Star Tribune wrote about Mullin's June 2005 disciplinary order by the board, which stated that Mullin failed to return credit balances in a timely manner, engaged in misleading advertising, performed hammertoe surgeries in which too much bone was removed, and other misconduct.