WASHINGTON, July 31: All Iraqi scientists so far interviewed by US officials have denied that the Saddam regime was making weapons of mass destruction, the Washington Post said on Thursday.

President Bush at a press conference on Wednesday said that with the help of these scientists US officials would soon unearth evidence to prove that Iraq had weapons of mass destruction. In the same news conference, Mr Bush also admitted using erroneous information about Iraq’s effort to buy uranium in Africa.

But the Post report said that “despite vigorous efforts,” the US government has so far found no Iraqi scientist to support its pre-war claims that Baghdad was pursuing an aggressive programme to develop nuclear, biological and chemical weapons.

The report, based on interviews with senior administration officials and members of Congress, said that so far US officials in Iraq had interviewed four senior Iraqi scientists and more than 12 at lower levels who worked for the Saddam regime. Some scientists have been arrested and held for months, others have made deals in return for information and at least one has agreed to be interviewed outside Iraq, the report said.

“All of the scientists interviewed have denied that Saddam Hussein had reconstituted his nuclear weapons programme or developed and hidden chemical or biological weapons since UN inspectors left in 1998,” the Post reported.

Several key Iraqi officials questioned the significance of evidence cited by the Bush administration to suggest that the ousted Iraqi president was stepping up efforts to develop new weapons of mass destruction, the report said.

The White House, for instance, has cited the case of nuclear scientist Mahdi Obeidi, who recently dug up plans and components for a gas centrifuge that he said he buried in 1991 at the end of the Persian Gulf War. The White House has pointed to the discovery as a sign of Saddam Hussein’s continuing nuclear ambitions. But Mr Obeidi told his interrogators that Iraq’s nuclear programme was dormant in the years before war began in March.

The sources told the Post that Mr Obeidi also disputed evidence cited by the US administration that Iraq had purchased aluminium tubes for a new centrifuge programme to enrich uranium for nuclear bombs. Mr Obeidi said the tubes were for rockets, as Iraq had claimed before the war.

CIA analysts do not believe he has told the whole truth, said one Bush administration official. Mr Obeidi has left Iraq under CIA auspices after being arrested briefly by US Army troops.

Jaffar Dhai Jaffar, who once was jailed by Saddam Hussein for not working on the nuclear programme and later came back to head it in the 1980s, was also interviewed recently by CIA personnel outside Iraq, and he, too, denied the nuclear programme had been restarted, the report said.

The Post also reported that the United States has used aggressive tactics to find and question key Iraqi scientists. Amir Saadi, Iraq’s 65-year-old chief liaison with UN weapons inspectors since last year, has been held incommunicado since his voluntary surrender in Baghdad to US military police more than three months ago.

Just hours before his April 12 surrender, Saadi gave a television interview to a German television reporter during which he said, “there were no weapons of mass destruction, and time will bear me out.” It is the same sentiment he sent to UN chief weapons inspector Hans Blix in a message that arrived at UN headquarters on March 19.

Saadi’s surrender encouraged the wife and daughter of Gen. Hossam Amin, head of Iraq’s National Monitoring Directorate, to get him to surrender, and he, too, has not been heard from since, the report said.

Since her husband’s his arrest, Helma Saadi said she has had no official notification of where he is being held. She has had only one communication with him, a June 15 letter delivered by the Red Cross.

Meanwhile, US troops are still arresting former government officials, scientists and professionals, the Post said.

On April 22 at 3 a.m, US soldiers backed by helicopters overhead, arrested Abdel Illah Hameed, the former Iraqi minister of agriculture. They knocked down the door of his house, searched the house and took Mr Hameed away, leaving his two older sons in plastic handcuffs that had to be cut away by a younger brother.