One of the world's leading human rights groups is battling a barrage of criticism for lashing out at Israel's record while allegedly soft-pedaling violations by Saudi Arabia.

The latest accusation against Human Rights Watch came from an unlikely critic Tuesday, as former chairman Robert Bernstein blasted the group he helped found for "helping those who wish to turn Israel into a pariah state."

Bernstein's charges, in an opinion piece published in The New York Times, revived debate over the organization that ranks as a respected leader in its field along with Amnesty International.

HRW, which counts over 275 staff members posted around the globe and publishes reports on some 90 countries each year, has been forced to issue a series of red-faced statements in recent months amid charges of anti-Israel bias and a soft stance toward authoritarian regimes.

Last month, the New York-based rights group temporarily suspended Marc Garlasco, a US senior military analyst, after it emerged he was an avid collector of Nazi memorabilia.

The former Pentagon official helped investigate and co-authored an HRW report on Israel's use of white phosphorus in the 22-day Israeli offensive on the Gaza Strip at the turn of the year that killed some 1,400 Palestinians and 13 Israelis.

An HRW delegation's May visit to Saudi Arabia also came under scrutiny, with opinion pieces in leading US and Israeli newspapers claiming the trip sought to raise Saudi money without criticizing Riyadh's rights record.

The allegations were echoed by Israeli Prime Minister Benjamin Netanyahu's office, the largest US pro-Israel lobby AIPAC and former Israeli minister Natan Sharansky, who claimed HRW "has become a tool in the hands of dictatorial regimes to fight against democracies."

The group, which began in 1978 as Helsinki Watch with a policy of publicly "naming and shaming" abusive governments, insisted it did not solicit funds from Saudi officials, noting it raises money from private sources and not governments.

Pointing the finger at HRW is merely a distraction, critics say.

"There is a very, very intense campaign dedicated to making sure that the conversation becomes about Human Rights Watch rather than the Israeli government's actions," said Daniel Levy, a former Israeli peace negotiator who heads the Middle East Task Force at the New America Foundation.

"The real thing that threatens Israel's legitimacy is the way it behaves and maintains the occupation, and it's a tragedy," he told AFP.

The row with Bernstein, the former HRW chairman, emerged at a critical time, amid a global spat over a damning UN report on the Gaza war that accused both Israel and the Islamist movement Hamas of war crimes.

Bernstein initially raised his concerns in April at a full meeting of HRW's Board of Directors, which "unanimously rejected" his claims, the group said.

"We fundamentally disagree with Mr Bernstein's views," HRW said in a statement Tuesday, adding that it "does not believe that the human rights records of 'closed' societies are the only ones deserving scrutiny.

"'Open' societies and democracies commit human rights abuses, too, and Human Rights Watch has an important role to play in documenting those abuses and pressing for their end," it said.

Bernstein, however, charged that HRW "casts aside its important distinction between open and closed societies" and Israel "faces the brunt of Human Rights Watch's criticism."

"There is a difference between wrongs committed in self-defense and those perpetrated intentionally," said Bernstein, who chaired HRW from 1978 to 1998.

He highlighted Israel's democratic record and said HRW had "lost critical perspective" as it "ignored" the plight of citizens of the Middle East's "authoritarian regimes."

HRW said its work on Israel is only "a tiny fraction" of its activities.

Out of 75 HRW reports this year, three dealt with rights concerns related to Israel, one looked at Palestinian militant groups' rocket attacks, another condemned political violence by Gaza rulers Hamas and three drubbed Saudi Arabia's rights record.

The group's annual world report also criticized those violations.