Scott Leckie, executive director of the Geneva-based Centre on Housing Rights and Evictions (COHRE), was speaking at a news conference on Wednesday where he launched a report on Israeli seizure of land and housing in Palestine since 1948.
"Although the US routinely supports the rights of refugees throughout the world to recover their former lands, homes and properties, it refuses to recognise that Palestinian refugees should also enjoy their legitimate property rights," he said.
"The hypocrisy of the US stance ... is blatant and unjustifiable if terms such as human rights and the rule of law are to have universal application," said Leckie, an international human rights lawyer.
More than four million Palestinian refugees and their descendants live in refugee camps in the West Bank, Gaza Strip, Jordan, Lebanon and Syria, having fled homes in what is now Israel during the Arab-Israeli wars of 1948-49 and 1967.
Palestinians want Israel to implement UN resolution 194, which says refugees have the right either to return to their original homes or receive compensation.
"Although the US routinely supports the rights of refugees throughout the world to recover their former lands, homes and properties, it refuses to recognise that Palestinian refugees should also enjoy their legitimate property rights"
COHRE executive director
Israel's government - with the support of US President George Bush's administration - refuses to admit refugees, fearing a large influx would mean demographic change for a state of 6.6 million citizens, of which 80% are Jewish.
Instead, Israel wants refugees resettled in a future Palestinian state and says it would contribute to a fund to compensate them.
Leckie said the US stance was surprising because Washington was supporting the return to Iraq of those Jewish Iraqis who fled their homes under the rule of former president Saddam Hussein.
The COHRE report cast doubt on the viability of a Palestinian state, a project the United States strongly supports, that might be created in any final peace agreements between Israelis and Palestinians.
The report showed, Leckie said, "that what little remains of the Palestinian homeland is disappearing in front of our eyes - it's as if Israel is deliberately erasing it from the map".
Settlements on the occupied territories and a proposal to create an Israeli corridor from Tel Aviv on the Mediterranean to the Jordanian border at the Dead Sea would make a viable Palestinian state "a practical impossibility", it said.
COHRE has offices around the world focusing on eviction issues and land and housing rights.
It receives financing from the governments of many European countries and of Canada, as well as from the US-based Ford Foundation.