A special legislative panel in Maryland, investigating the large payout and questionable reimbursements that Gov. Larry Hogan’s former chief of staff received at his previous job, voted unanimously on Wednesday to issue a subpoena to force the official to testify.

It is the first time in 14 years that the Legislative Policy Committee, which is led by the Senate president and House speaker, has invoked its authority to issue a subpoena for a member of the executive branch.

The 2006 subpoena targeted Hogan, who at the time was appointments secretary to Gov. Robert L. Ehrlich Jr. (R). The future Republican governor was forced to answer questions before the panel about what was thought to be an effort by the Ehrlich administration to target Democrats for termination from state jobs.

“Allegations of corruption and misuse of power are serious, and they require immediate attention,” Senate President Bill Ferguson (D-Baltimore City) said in reference to the desire to question Roy McGrath, who left his position as director of the Maryland Environmental Service in June to become Hogan’s top aide.

“It is too important that we have the facts to make the appropriate decision,” Ferguson said. “We cannot wait . . . to restore faith and trust in Maryland government.”

McGrath and Matt Sherring, who served as director of operations for the Maryland Environmental Service, will be required to appear before the Joint Committee on Fair Practices and State Personnel Oversight within 30 days, according to the bipartisan vote. Both have declined past requests to appear.

McGrath’s attorney, Bruce Marcus, said his client is “willing and available to address appropriate questions and to the extent possible present a full accounting of relevant events.”

Sherring could not immediately be reached for comment.

Earlier Wednesday, Hogan announced several proposals to restructure the Maryland Environmental Service, a nonprofit business unit of the state that handles environmental and public works projects, including dredging operations, and building, designing and operating landfills. Ninety percent of the agency’s contracts are with state and local governments, which means it is largely publicly funded.

The proposed changes are the governor’s latest effort to show concern about and distance himself from the severance package and benefits paid to McGrath, who has said Hogan knew of and approved the arrangements.

“Recent developments have brought to light serious issues with regards to the lack of financial oversight and controls in place at the corporation, including concerns with how MES handles expense reimbursements, salaries, and bonuses, and their long-standing practice of paying generous severance packages to departing executive directors,” Hogan — who strongly denies approving McGrath’s payments — said in a statement.

Hogan offered three ways to reform the agency: changing its oversight, restoring it to a full state agency or selling it to a private company.

McGrath received nearly $250,000 in severance from the Maryland Environmental Service just days before he took the job in the governor’s office.

After those payments became public, McGrath resigned as Hogan’s chief of staff, and Ferguson and House Speaker Adrienne A. Jones (D-Baltimore County) launched their investigation.

Over the past several weeks, McGrath has refused requests by the Joint Committee on Fair Practices and State Personnel Oversight to address the hundreds of thousands in bonuses awarded each year; trips across the country and around the world; big payouts for retirement; and expense reports that include luxury resort hotel rooms and $5 hot fudge sundaes.

In emails to The Washington Post, McGrath has defended the payments, describing the structure and mission of the environmental service agency as more akin to the private sector. He said the agency experienced major growth during his tenure, which allowed all of its employees to receive bonuses.

Without McGrath’s testimony, Del. Erek L. Barron (D-Prince George’s), who co-chairs the joint committee, said the probe has an unclear picture.

“It’s hard to get at the bottom and understand the justification and rational for these expenses,” agreed his co-chair, Sen. Clarence K. Lam (D-Howard).

Hogan announced last month that he was ordering an audit of the Maryland Environmental Service and would work with the legislature to increase oversight and tighten rules governing the agency.