The former UN chief weapons inspector in Iraq, Richard Butler, says his phone calls at the United Nations were bugged during his tenure from 1997 to 1999.
Butler says his negotiations on Iraq were secretly monitored
He told Australian radio at least four UN Security Council members monitored his calls, and he would leave the UN building if taking a confidential call.
ABC Radio cited Australian intelligence sources as saying Hans Blix, the last weapons inspector, was also bugged.
Ex-UK minister Clare Short says the UK bugged UN Secretary-General Kofi Annan.
"Of course I was (bugged)," Richard Butler told ABC radio.
"I was well aware of it. How did I know? Because those who did it would come to me and show me the recordings that they had made on others to help me do my job disarming Iraq."
Mr Butler said he was bugged by the Americans, British, French and Russians.
"I knew it from other sources," he said. "I was utterly confident that I was bugged by at least four permanent members of the Security Council."
He said that if he needed to make a private call to his contacts, he would leave the UN building in New York and either go to a busy cafe or walk in Central Park.
Meanwhile ABC reporter Andrew Fowler said he had been told by Australian intelligence contacts that Hans Blix - the UN's most recent weapons inspector in Iraq - was also tapped.
"That's what I'm told, specifically each time he entered Iraq, his phone was targeted and recorded and the transcripts were then made available to the United States, Australia, Canada, the UK and also New Zealand," he said.
The United Nations has already said that any bugging of UN offices would be illegal and should end immediately.
The organisation was responding to claims on Thursday by the former UK cabinet minister Clare Short that British intelligence monitored calls by UN Secretary-General Kofi Annan.
On Friday, Ms Short hit back after UK Prime Minister Tony Blair branded the claims "deeply irresponsible".
She denied putting the UK or its security services at risk by her revelations, and accused the prime minister of using "pompous" distraction tactics.
At his monthly news conference, Mr Blair insisted the UK security services acted in accordance with domestic and international law and in their country's best interests.