The Lock The Gate Alliance has apologised to Origin Energy and the Scientific Inquiry into Hydraulic Fracturing in the NT for its “scandalous allegations”.

The anti-fracking group alleged that Origin had been involved in a “cover-up” of information and accused it of omitting an important diagram of a well deformation.

But the the inquiry's chair, Justice Rachel Pepper, has rejected the claims and called on Lock The Gate to apologise.

“Given the scandalous nature of your allegations against Origin and the inquiry which have now been proven to be wholly incorrect, it remains a matter of considerable concern that no apology has been proffered by you, on behalf of Lock the Gate, to Origin or the inquiry,” she said.

“Failure to do so has the very real effect of impugning the credibility of yourself and Lock the Gate.”

Lock The Gate spokesperson Naomi Hogan said the group “apologised unreservedly”.

“We want to make it clear that in raising the issue we did not intend to impugn the integrity of the panel in anyway whatsoever,” she said.

“We believed at the time it was a reasonable concern to raise based on the information before us.

“We appreciate the panel has now looked into the matter and concluded that the matter did not involve a cover-up and we sincerely apologise for any adverse impact the allegations had on the panel or Origin.”

Justice Pepper accepted the apology.

Origin says it is “still awaiting a similar apology”.

“This is a really important issue and we welcome a healthy debate,” the company said in a statement.

“But it has to be based in truth and not driven by false information, which is what the inquiry witnessed last week and I think unfortunately what many in the community has heard in this whole process.”