Better to assess first than act: inquest

A senior NSW police officer has told the inquest into the Sydney siege his focus was first on assessing hostage taker Man Haron Monis.

File image of flowers laid outside the Lindt Cafe in memory of the Sydney siege victims Source: AAP

The first high-ranking police officer to take charge at the Lindt Cafe siege has told an inquest it was important to assess the situation before entering the building.

NSW police Assistant Commissioner Michael Fuller was in command from 9.50am to 12.10pm on the morning of the siege, on December 15, 2014, and has told the coronial inquest into the matter that he initially ordered a "contain and negotiate" response.

"There was no active shooter," Mr Fuller said on Tuesday while describing the incident's early moments.

At this stage police were uncertain about how many captives were inside and would not have stormed the building unless hostage taker Man Haron Monis had started shooting, he said.

"There was no information to suggest there is any immediate threat in that environment to any of the hostages," he said.

"There was an enormous amount we needed to know."

Mr Fuller said he had dealt with countless sieges in the past, usually about one a month resulting from botched crimes or troubled domestic situations.

"Contain and negotiate has been a resolution where no one has lost their lives," he said.

While in charge Mr Fuller was able to assemble and dispatch teams to deal with three bomb threats Monis had made.

Nothing was found at Circular Quay, the Seven Network headquarters or at George Street - the locations at which Monis had said there were explosives stashed.

But, Mr Fuller said, police were still uncertain whether Monis had a bomb in his backpack.

"He had a real firearm, he's taken hostages, he's gone to these lengths, it's not unreasonable to think that he has an explosive device on him," he said.

The siege reached its deadly conclusion after 17 hours when officers stormed the Martin Place building following Monis's point blank murder of Tori Johnson.

Monis was gunned down and barrister Katrina Dawson also died after being hit by shrapnel from police rounds, fired as they entered the cafe.

Mr Fuller will continue evidence on Tuesday afternoon.