A former high school principal is facing charges of professional misconduct after being accused of tampering with Ontario's literacy test.

The Ontario College of Teachers said it conducted an investigation and found that some students were called back to the school to complete parts of the Ontario Secondary School Literacy Test in March 2016 after it was supposed to be concluded.

Christine Vellinga, who was then a principal with the Simcoe Muskoka Catholic District School Board, is accused of reviewing test booklets to find incomplete tests, and telling certain staff members to do the same.

A notice of a disciplinary committee hearing from the college alleges Vellinga called 21 students back to school to complete portions of the test they had missed, directing them to specific parts of the booklet -- and asked the acting vice-principal to do the same.

The college didn't name the school Vellinga worked at, but noted that she has since been demoted to a vice-principal and was suspended without pay for 20 days.

Vellinga is also accused of not ensuring that students were properly supervised while in possession of the test and allegedly telling one student, "you were never here."

She is expected to appear before a disciplinary committee later this month. Her lawyer did not respond to a request for comment.

Also accused in the case are the acting vice-principal, as well as a teacher who allegedly helped determine which students had not completed the tests. Andrew Burke, the acting vice-principal, was suspended by the school board without pay for 10 days, and Gregory Quinn was suspended for five days. Dates for their disciplinary hearings have not been announced.

Lawyers for Burke and Quinn did not respond to requests for comment.

The school board's director of education said in a statement Friday that it was "very concerned" when it learned of the alleged test tampering.

"We immediately conducted an investigation, reported the incident to the Ontario College of Teachers and addressed the issue directly with those involved," said Brian Beal, adding the board would not comment further while the issue was under investigation.

The Education Quality and Accountability Office, which creates and administers the test, conducted an investigation into the alleged tampering, and found that it did in fact happen. As a result, it withheld the school's results of that year's tests from its reports.

The EQAO says the results of the tests are used to produce annual school board reports and to track children's progress throughout their schooling.

Steven Reid, EQAO's Chief Assessment Officer, said the test results are one piece of a "data tapestry," woven together with information from different sources to evaluate school performance. He said EQAO data shouldn't be taken alone as a marker of a school or school board's success or failure.

But some experts say Vellinga's case highlights a broader problem with how administrators see the role of EQAO tests.

"Unfortunately, sometimes, depending on the school board or superintendent or even a principal, they're feeling pressure to be great in terms of what the results are," said Charles Pascal, a professor at the Ontario Institute for Studies in Education at the University of Toronto and a former chair of the EQAO.

"Sometimes because of leadership and how the purpose of the testing is conveyed, people and individual teachers feel a pressure that they shouldn't be feeling."

Some of the pressure could come from the fact that EQAO results are made public, Pascal suggested.

He noted that EQAO results are often used by real estate agents in advertising different neighbourhoods, which puts great pressure on schools to perform well.

It is natural, however, that school administrators would want to do well on the tests, said Don Klinger, a professor of education at Queen's University who has worked as a consultant and on various panels for the EQAO.

"We should be striving to do the best for our teachers and for our students that we work with," he said. "There's different ways of tipping the scale in your favour. Some are legitimate -- one's called 'good teaching."'