The ultra-conservative Heartland Institute has called on Oxford University to ban a lecture by the scientist who used deception to expose its mission to discredit climate science.

Peter Gleick, the water expert who admitted to and apologised for carrying out an exposé of confidential Heartland materials, is due to speak on 24 April as part of a prestigous lecture series.

The annual Oxford Amnesty lectures are an important fundraiser for Amnesty International, although they are not directly organised by the human rights organisation or by the university.

This year's theme of the lectures is Protect the Human/Protect the Planet. Gleick is an internationally recognised water expert.

However, Heartland Institute argued that Gleick should be barred from appearing at Oxford because of his admitted role in tricking the thinktank to turn over confidential documents outlining its fundraising plans and key donors.

Heartland says one of the documents is a fake, and accused Gleick of the forgery. Gleick has apologised for his role in the affair.

The documents, which revealed a project to sway teaching of science to children in kindergarten, sparked a furore about the role of Heartland and its network of paid bloggers and experts in influencing public attitudes on climate change.

The revelations were not surprising to campaigners, who were familiar with Heartland's climate mission. However, they did bring embarrassment to some of Heartland's corporate donors. General Motors last month pulled its funding from Heartland.

The documents – or at least the manner in which they were obtained – also proved damaging to Gleick, who was forced to take a leave of absence from the Pacific Institute, which he founded and had led before the release.

A number of scientists have said Gleick's conduct was wrong, and that he set back the cause of climate change. Some campaigners, however, cast him as a hero.

In a statement emailed to reporters, Heartland's president, Joseph Bast, said Oxford should not allow Gleick to appear.

"All honest scientists should be outraged that Oxford University should honor Gleick with a guest lecture," he said. "The actions Gleick has admitted to having taken – lying repeatedly and committing fraud, and then denying responsibility and refusing to take corrective action – all make him unqualified to speak to students or as a scientist."

Bast went on to say that Oxford "should be ashamed" of the association with Gleick. "John Locke, Linus Pauling, and Edwin Hubble must be spinning in their graves.

"The members of the scientific community who invite him to speak are sullying their own reputations. How can you respect a scientist who committed fraud and theft? How can the public trust the veracity of Gleick's science after his confessed deceptions? The answer to both questions is: you can't."

The strong language is typical of Heartland, which has repeatedly warned of legal action against Gleick.

There was no immediate comment from the organisers of the lecture series, who work on a volunteer basis. However, a spokesman for Amnesty said the organisation would be discussing the matter with the lecture body.

Gleick had no immediate response. However, the Pacific Institute confirmed that he planned to go ahead with the lecture.

Gleick has been on leave as president of the Pacific Institute pending a board investigation into his conduct. However, he appeared as a keynote speaker at a California water conference, just 10 days after he went on temporary leave. He has also returned to Twitter, after a short hiatus.

A spokesman from the Pacific Institute on Wednesday would not identify the independent firm conducting the investigation into Gleick, or say when the results would be made public.

Gleick's high-profile activities since the unauthorised release have infuriated Heartland.

Spokesman Jim Lakely said in an email: "I think it's a travesty. He supposedly took a 'leave of absence' from heading up the Pacific Institute, but never left. Gleick is still listed as the organisation's president, and seems to have suffered no changes in his schedule. He simply continues along as if he didn't commit the fraud, theft and defamation to which he confessed.

"The Pacific Institute should answer for that farce."