A Sydney radio has reported that the gunman who is holding up dozens of people hostage in a CBD cafe had called the station and asked to speak on radio.
The man told negotiators he has "devices all over the city" and wants to "speak with the prime minister (Tony Abbott) live on radio".
2GB radio host Ray Hadley has said the gunman had made contact with him through a hostage, trying to get his message out on air.
The siege at the cafe began Monday morning after an armed man, showing Islamic flags, took up to dozens of people hostage.
But Hadley said he refused to enter into negotiations or broadcast any demands from the man, publicly urging him to talk to police instead.
"The media can't play a role in negotiating with people purporting to be from Islamic State holding hostages at a cafe in Sydney," Hadley said.
"It is the job of authorities to solve this problem...who have the expertise to deal with these matters, not with radio broadcasters."