The New South Wales police commissioner Andrew Scipione said investigation will continue as the Sydney hostage drama entered its 11th hour.

When asked by the local press on the motive of the siege, Scipione was more concerned on the investigation.

"We are not in the business of speculating. We are in the business of investigation. We will continue with this investigation. I can assure you we are doing absolutely all we can. We can do even more to guarantee the safe release of the all these people," he told the press.

He also declined to go into detail on how many people are still in the Lindt cafe.

"We will not go into detail on who is in there, how many people are in there. We are not in the position to do that at the moment," he said.

When asked by a reporter if the five hostages were released or they escaped, Scipione said: "We are not going to talk about how that happened. We are pleased to see them out," he said.

On managing the crowd of onlookers, Scipione advised local residents not to be around the area as "there is nothing to be seen."