Lawyers representing child abuse survivors have called for the environment secretary, Michael Gove, to be called before a public inquiry over an allegation he intervened in a sexual abuse investigation at a boarding school.

Two child abuse professionals have testified at the ongoing independent inquiry into child sexual abuse (IICSA) that while he was the education secretary, Gove intervened to find out about an investigation into a priest suspected of abuse at Downside Abbey school in Somerset.

Gove has denied the allegation, adding that there are no official records of such an intervention.

The inquiry into child sexual abuse published a damning report on Downside and another leading Catholic school, Ampleforth, on Thursday, saying the true scale of sexual abuse at the schools over a period of 40 years was likely to have been far greater than had been proved in the courts.

The inquiry said there was “insufficient evidence” to draw any conclusions on the allegation relating to Gove.

Two lawyers representing child abuse survivors have called for the cabinet minister to give evidence in person at the inquiry.

David Enright, one of the lawyers, said: “This report represents an impressive piece of work by the inquiry and its legal team, and must be commended. However, we are concerned about the allegation that Michael Gove intervened in relation to an investigation of sexual abuse at Downside.

“This is an allegation made by two apparently reliable witnesses about a senior member of the government. The minister in turn has said it did not happen. It needs to be cleared up. There is a simple solution to this: call Mr Gove to give evidence before the inquiry at one of the two scheduled further hearings in this important investigation.”

Another lawyer, Richard Scorer, said that given the conflicting evidence, it was right to invite the minister and one of the child abuse professionals to give oral evidence to resolve the matter.

Clare Winter, the deputy director of children’s services responsible for children’s social care at Somerset county council, told the inquiry in 2017 that she received two telephone calls in 2010 from Gove and his office inquiring about the investigation.

The second call, she said, came from “somebody who said they were the secretary of state for education” who repeated a request for information about the progress of the investigation into a priest, known only as F65, suspected of having oral sex with a 16-year-old boy.

She said she did not disclose any information. She told the inquiry the incident was “so unusual. I have never experienced it before or since”.

Jane Dziadulewicz, another safeguarding official responsible for child protection, told the inquiry that she helped produce a report for Gove’s office on the progress of the Downside investigation following the calls.

Following testimony from the pair last year, the inquiry initiated a deeper examination. In a witness statement, Gove said neither he nor members of his office had called Winter. He added that there were no official records of such calls.

“I think it extraordinarily unlikely that I would have made such a call. I cannot conceive of the circumstances in which I would have wished to do so … The only possible explanation for Ms Winter’s evidence is that she is labouring under some kind of misunderstanding,” he said.

The Somerset MP Jacob Rees-Mogg, who has connections to Downside school, has previously not responded to the Guardian’s questions about whether he had discussed the investigation with Gove.

In a witness statement, Winter said: “I did not expect someone saying they were the secretary of state to contact me and have no reason to doubt who they said they were.”