Cheating on standardized tests in the District would be illegal under a bill introduced in the D.C. Council, and a teacher or principal found guilty of violating the law would lose his professional license and face a fine of thousands of dollars.

The measure — which council member David A. Catania (I-At Large) and colleagues Mary M. Cheh (D-Ward 3) and Marion Barry (D-Ward 8) introduced Tuesday — comes in response to persistent allegations that cheating led to inflated scores in some D.C. public schools between 2008 and 2010.

“District parents deserve a testing system where cheating does not occur and, more importantly, where cheating cannot occur,” Catania said. “And our educators deserve to have student gains beyond dispute or reproach.”

Eight other council members signed on as co-sponsors, and a spokesman said Mayor Vincent C. Gray (D) supports the measure.

The Office of the State Superintendent of Education (OSSE) publishes testing guidelines that require the D.C. Public Schools system and each independent charter school to create a test-security plan and outline sanctions for employees who violate procedures.

The bill introduced Tuesday would for the first time turn those expectations into law. The OSSE would be responsible for enforcement.

OSSE officials said the proposal does not appear to depart significantly from current guidelines. D.C. school system officials said they were still reviewing the legislation and declined to comment.

The D.C. Public Charter School Board is not opposed to the bill, spokeswoman Audrey Williams said. The charter board monitors security protocols at some schools, and if the bill transfers that responsibility to the OSSE, “we have no problem with that,” Williams wrote in an e-mail.

Suspicions of widespread cheating in D.C. schools have simmered since 2011, when USA Today published an investigation showing that more than 100 schools had an unusually high number of wrong-to-right erasures on student answer sheets. Such erasures, experts have said, could indicate cheating.

Several investigations followed, including by D.C. Inspector General Charles Willoughby and the U.S. Education Department’s Office of the Inspector General. Those probes found isolated instances of cheating but cleared the school system of widespread wrongdoing.

Skeptics have continued to question whether the investigations were thorough enough to find the truth. Questions intensified last month after news that a former principal had filed a federal whistleblower complaint alleging “systemic” cheating at her school, Noyes Elementary.

The principal, Adell Cothorne, also alleged on national television that she witnessed suspicious behavior among teachers at Noyes. When she tightened test security out of concern about cheating, the school’s test scores fell by more than 25 percentage points.

The revelations led to calls for the council to investigate further. Catania, chairman of the council’s Education Committee, said in an interview that he doesn’t have the staff or resources to replicate the work of previous investigators and that he would rather concentrate on ensuring that future tests are secure.

The bill specifies behaviors that would be illegal, including changing students’ answers, looking at test questions before the test is administered, coaching students toward correct answers, possessing test materials outside of specified testing times and leaving secure test materials unattended.

Violators would not be subject to criminal charges but to administrative sanctions that the OSSE would impose. Such sanctions could include a fine of up to $10,000 for each violation, having to pay any costs the city incurs while dealing with the security breach, and revocation or suspension of an employee’s professional credentials.

At least 10 states have test-integrity laws on the books, Catania said. Among them is Virginia, where teachers caught violating test-security measures can lose their licenses or be fined.

The D.C. measure was referred to the Education Committee, as were two other school-related bills introduced Tuesday.

Wading into the battle over Chancellor Kaya Henderson’s plan to close 15 city schools, Barry introduced a bill to give the council say over school closures. He said the measure would “provide for more checks and balances” on the chancellor and mayor, who have unilateral authority to close schools.

It’s not clear that Barry’s colleagues want to enter the school-closure fray. Only one member — Yvette M. Alexander (D-Ward 7), who has called for a moratorium on closures in her ward — joined as a co-sponsor.

Jack Evans (D-Ward 2) introduced a bill that would require all D.C. public schools to employ a full-time librarian as well as art, music and physical education teachers.

“We are spending far too much money to not have these available to our children,” said Evans, who was joined by seven co-sponsors.

A similar bill Evans proposed last year went nowhere.

A spokeswoman for the school system said officials were reviewing both bills and could not comment.