The UN has roundly rebuffed remarks by the South African judge Richard Goldstone that cast doubt on the report into the Gaza war that bears his name, causing rifts within the UN and furious debate across the Middle East.

In the first public sign of a split within the four-person committee that compiled the report into the Israeli attack on Gaza in December 2008, the Pakistani human rights lawyer Hina Jilani has openly contradicted Goldstone's comments. In an interview with the Middle East Monitor, she said that the UN report still stood.

"No process or acceptable procedure would invalidate the UN report; if it does happen, it would be seen as a suspect move. The UN cannot allow impunity to remain, and will have to act if it wants to remain a credible international governing body," she said.

Jilani sat with Goldstone on the fact-finding mission that looked into allegations of war crimes committed by both Israel and Hamas during the three-week war. The other two members of the committee, Christine Chinkin and Desmond Travers, could not be reached for comment.

Goldstone made his remarks in an article in the Washington Post in which he said that he regretted aspects of the report that he chaired, including the suggestion that Israel had intentionally targeted civilians. Had he been aware of evidence that had since come to light, he wrote, "the Goldstone report would have been a different document".

In a further indication of his U-turn, the Israeli paper, Yediot Ahronot, said the judge planned to press for his report to be nullified.

The report, published in September 2009, found that Israelis involved in the Gaza war should face "individual criminal responsibility" for potential war crimes. Some 1,400 Palestinians died, at least 50% of whom were civilians, and 13 Israelis.

But the inquiry was carried out without Israeli co-operation, and information uncovered by Israel's own investigations since then had changed his understanding of events, Goldstone said.

Though the judge's comments have rekindled the heated debate that followed the Gaza war, they are unlikely to lead to any immediate action on the part of the UN. Cedric Sapey, spokesman for the UN human rights council that commissioned the report, said: "The UN will not revoke a report on the basis of an article in a newspaper. The views Mr Goldstone expressed are his own personal views."

A move to change or withdraw the report would either require a formal written complaint from Goldstone, backed unanimously by his three fellow authors, or a vote by the UN general assembly or the human rights council, Sapey said.

Israel has leapt on the Goldstone article, arguing it proves that the original UN report was flawed. The interior minister, Eli Yishai, said he had contacted Goldstone to thank him. "As a Jew, he understands well the story of the Jewish people's suffering," he told Israeli army radio.

An Israeli official said the government would now try to get a re-evaluation of the report as well as "asking our legal experts to see how it affects the legal harassment" of Israeli politicians and officers, particularly in the UK.

Goldstone's article comes at a particularly sensitive time for Israel. The human rights council has recommended the UN general assembly passes the Gaza report to the security council with the aim of referring both Israel and Hamas to the international criminal court for alleged war crimes. Any such move would almost certainly be blocked by the US, Israel's main ally, which has the power of veto, though a referral could still prove politically damaging.

The Palestinian ministry of foreign affairs said Goldstone's intervention was immaterial. "The Goldstone Report remains a valid and important document highlighting the need for a full and genuine investigation. Nothing in Justice Goldstone's personal comments changes the essential need to provide the victims of the assault on the Gaza Strip with access to justice."

Khalil Shiqaqi, a Palestinian political scientist, said it was clear that no one had read exactly what Judge Goldstone had written. "The Israelis think that Goldstone has overturned what was written in his report and the Palestinians have taken their cue from them. What he has actually done is slightly modified his controversial view that Israel had deliberately targeted civilians. Very few people among the international community or non-governmentable bodies said the same thing.

"If he retracted one thing, there was much he did not retract, such as Israel's deliberate destruction of houses in the Gaza Strip."