A top assistant to Wayne County Executive Robert Ficano told county commissioners Tuesday that an investigation into a controversial $200,000 severance has "made substantial progress," but said he can't say much else about the issue.

Assistant County Executive Alan Helmkamp acknowledged that Turkia Mullin also received payment for 75 percent of the worth of 20 unused sick days and an unspecified number of vacation days per a letter dated Sept. 3 when she left to become CEO of Detroit Metropolitan Airport.

He didn't know the monetary amount of that payout. If it was based on her $200,000 salary, the sick days alone would be worth about $12,500.

The document also outlines plans for her severance. It is signed by Mullin and Tim Taylor, a former top executive in human resources now working part time on an hourly basis with no benefits.