An investigation into allegations of administrator-perpetrated grade changing at New Haven’s Hillhouse High School is underway.

The allegations of misconduct first became public at a Board of Education meeting two days before Christmas, with Hillhouse principal Kermit Carolina accused of at least three cases of changing students’ grades. But Carolina defended himself by arguing that he had merely been fixing errors made by the school’s grading system and that the probe against him was politically motivated.

At the Dec. 23 meeting ­— which school board officials did not schedule far enough in advance for a public notice and about which they did not inform any media — New Haven Public Schools Superintendent Reginald Mayo told the board that an investigation had been launched into grade or credit “adjustments” at the school, potentially impacting several students. But Carolina said at the meeting that it was retaliation from another administrator who he had “challenged” and from Mayor John DeStefano Jr. for Carolina’s decision to not appear at a DeStefano campaign event last fall, according to the New Haven Independent.

“It saddens me to stand here due to baseless allegations against my high school,” Carolina said at the meeting. “I’ve always been transparent.”

Carolina produced a handwritten note addressed from DeStefano to him that only read, “You were there,” which Carolina said referred to his presence at a campaign event for DeStefano’s challenger, Jeffrey Kerekes. But DeStefano later explained that the note was from a Sept. 5 road race he attended where he took photographs of city and school workers, and later sent them the photos with handwritten notes, according to the New Haven Register.

DeStefano added that he had no connection to the school’s grade-changing investigation.

“This is an internal issue that’s coming out of Hillhouse High,” DeStefano said after the meeting, according to the Independent. “To suggest it’s something else — I have no basis for that.”

The school board hired Milford attorney Floyd Dugas to perform the investigation, although Carolina and his attorney Michael Jefferson, the father of a Hillhouse student, asked to have Dugas to be removed from the case due to donations from members of his law firm and family to DeStefano’s campaign last year. The board refused, and the probe continued, according to the New Haven Independent.

But after Dugas interviewed Carolina for the investigation, Jefferson said a new issue surfaced: Tenex, the program Hillhouse uses to record grades. The attorney said the program has a glitch that causes it to record lower grades, a fact backed up by several Hillhouse teachers who reported in a staff meeting that they had faced problems with Tenex, according to the New Haven Register.

Jefferson also said that the cases of grade changing initially investigated involved students not receiving the appropriate credit for classes they took during the summer, which were changed in order to reflect the correct level of difficulty. He added that Carolina doesn’t even have access to the grading computer system, and expects the electronic investigation into who changed the grades to show that his client did nothing wrong.

When reached by email, Ferdinand Risco, a Board of Education vice president, said that the board’s members will not comment on the case while the investigation is ongoing.

Many supporters of Carolina — Hillhouse parents, students, aldermen and other community leaders — spoke at a Board of Education meeting last week, calling Carolina a “father figure” and praising his work at the school.

“Many of us sent our kids to Hillhouse because of Kermit Carolina,” said Dana Griffin, a parent of a Hillhouse student who serves on the school’s parent-teacher organization, according to the Independent. “Now we wonder — how do you get this reputation back?”

While many of Carolina’s supporters asked the district not to fire the principal, he told the New Haven Independent that he was not worried about the outcome of the investigation because he had not done anything wrong.

Nearly 1,000 students attend Hillhouse High School.