From left, Kevin Maxwell, chief executive of Prince George's County Public Schools, and Rushern L Baker III, county executive, speak to reporters at Suitland Elementary School in 2017. (Donna St. George/The Washington Post)

Maryland education officials on Tuesday called on Prince George’s County to prove it is fixing problems uncovered in a diploma scandal and took the unusual step of assigning a state employee full time to monitor those efforts for the next year.

The actions were recommended Tuesday by state Superintendent Karen B. Salmon and drew unanimous support from the Maryland State Board of Education a month after Prince George’s leaders appeared before the panel.

Under Maryland’s plan, the state will seek periodic written reports on the county’s progress in fixing what went wrong and request an outside audit afterward to ensure problems are resolved. At least one state employee would be tapped to track compliance as efforts are underway.

“It’s another set of eyes to look at grade-changing policies, ­student-attendance policies, as they relate to earning that Maryland high school diploma,” Salmon said in an interview.

Andrew R. Smarick, president of the state Board of Education, said the panel was alarmed by findings of a state-ordered investigation, conducted last fall after allegations of graduation rate fraud in the state’s second-largest school system.

“Too many students were graduated despite falling short of the expectations we had,” he said. “Unfortunately, this does a disservice . . . and this undermines the value of a Maryland diploma.”

Smarick said the board hoped the measures would “ensure this doesn’t happen again.”

“The state just needs to be confident that the district’s graduates have earned their diplomas,” he said.

The graduation rate probe has become fodder for political opponents of Prince George’s County Executive Rushern L. Baker III (D), who is running for governor based in part on his efforts to overhaul schools.

Baker — who wrested control of the troubled system from the county’s elected school board during his first term — has been sharply criticized by the county teachers union and by his potential gubernatorial rivals. The Prince George’s County Educators’ Association in a vote last week indicated its lack of confidence in the school board’s current structure and asked the state legislature to strip Baker of the power to appoint members.

The follow-up audit requested by the board would resemble the investigation done last fall, examining the same issues to make certain that proposed changes are in place and working, state officials said. It would look at the Class of 2018 and possibly the following year.

Told of the state’s actions, school system officials Tuesday said Kevin M. Maxwell, the district’s chief executive, had already proposed a second audit as part of the district’s plan for remedying problems.

“We agree on that step to ensure academic integrity, and we have worked with the state closely on this, and we look forward to continuing that partnership,” said district spokesman John White.

White asserted that many of the problems described in the report related to a sample of students with late grade changes. “It is not a description of our entire school system,” he said. “However, many of the problems identified, we’ve already begun fixing.”

At the Board of Education’s previous meeting, Maxwell and five other Prince George’s officials faced tough questions about the system’s practices and attributed the scandal to failures in procedure and monitoring, not pressure from the top.

The board asked about high levels of student absences, problems in district culture and diminished community trust.

The controversy comes as D.C. Public Schools also has been mired in a diploma scandal.

In Maryland, the controversy goes back to last spring, when a minority bloc on the school board wrote to Gov. Larry Hogan (R), saying that whistleblowers had come forward with evidence that grades and credit counts were manipulated to boost graduation rates.

State lawmakers from Prince George’s soon echoed the call for state action, and Hogan in June asked the Board of Education for a “complete, thorough and exhaustive” investigation.

The county’s four-year graduation rate climbed more than seven percentage points from 2013 to 2016, when it reached 81.4 percent — the largest jump for that period of any school system in the state. Recent figures show it edged up again in 2017, to 82.7 percent.

The state board hired an independent auditor to conduct the examination — the D.C. firm Alvarez & Marsal — and in early November released a report that showed grades for nearly 5,500 students were changed days before graduation during the past two years. It pointed to problems with documentation and high levels of student absences.

About 30 percent of students in a sample group with late grade changes were not eligible to graduate or lacked adequate documentation, the report said.

Prince George’s officials have pointed out that the report found no evidence that grade tampering or improper activity was ordered by the district’s leadership.

But critics disputed the assertions last month when an email from a central office staff member surfaced showing that less than three weeks before graduation in 2016, one high school — DuVal — was showing a preliminary graduation rate of 59 percent. By the time the final count was in, the graduation rate had risen to 92.4 percent.

Prince George’s officials said in January they removed some staff members at DuVal amid findings that grading and graduation certification procedures were violated. County officials told the state board last month that five or six employees had been disciplined.

Rachel Chason contributed to this report.