The former Australian diplomat said he had seen intelligence when he headed the UN team in Iraq from 1997 until 1999 which seemed to indicate Syria had helped keep Iraq's weapons of mass destruction hidden.

"I was shown some intelligence information, from overhead imagery and so on, that the Iraqis had moved some containers of stuff across the border into Syria," Butler told ABC Radio.

"We had reason to believe that those were containers of chemical weapons and perhaps some other weapons.

"I don't believe the Iraqis wanted to give them to Syria, but I think they just wanted to get them out of the territory, out of the range of our inspections. Syria was prepared to be the custodian of them."

Butler, who opposed the war in Iraq, aired his views on the issue as US officials turned up the heat on Syria, accusing it of harbouring Iraqi leaders, supporting terrorists and having its own weapons of mass destruction.

US President George W Bush said said US intelligence indicated Syria had stockpiles of chemical weapons, including the deadly nerve gas sarin.

He warned Damascus not to allow any senior Iraqi leaders to escape into Syria in an effort to flee coalition forces.

Syria has denied the accusations and in turn said Washington was trying to divert attention from the deepening chaos and looting in Iraq.

Australian Foreign Minister Alexander Downer said Canberra was also aware of intelligence reports that Iraqi weapons, including chemical weapons, may have been moved into Syria.

But Downer ruled out the possibility of a military attack on Syria, saying diplomatic pressure would be placed on Damascus because of its decision to leave open its border with Iraq and to allow Iraqi figures to escape.

"Not surprisingly those factors have annoyed the Americans substantially," Downer said.

"But I wouldn't extrapolate from that that the Americans were about to launch, or would quite soon launch a military attack on Syria. There's no prospect of that."

SPACE.WIRE