Vermont Attorney General T.J. Donovan said his office has concluded an investigation into the invoices and billing practices of Dr. Jonathan Gruber, an economic consultant who contracted with the state to provide policy expertise, research and economic modeling for Vermont’s abandoned single-payer healthcare system.

Former Gov. Peter Shumlin sought to create the single-payer system, known as Green Mountain Care, but eventually walked away from the plan after determining it would cost too much. The attorney general’s office’s began the investigation into Gruber’s billing after receiving a referral by State Auditor Doug Hoffer.

Donovan said Thursday his office and Gruber reached an agreement to settle the state’s potential legal claim that Gruber submitted false claims to the state under Vermont’s Civil False Claims Act. Donovan said his office concluded that Gruber’s conduct violated the Vermont Civil False Claims Act. Gruber denied a violation, but in order to resolve the case, he agreed to forgo any further payments from the state that he might be owed.