Authorities will launch an investigation into how, with such a chequered history, Sydney siege gunman Man Haron Monis, was allowed to walk the streets.

The NSW state government today admitted the 50-year-old self-proclaimed Muslim cleric, also known as the “Fake Sheikh”, slipped through the cracks of both security and policing agencies.

NSW Attorney-General Brad Hazzard said authorities are now investigating the man’s past. He’s been known to authorities for years.

“We are asking state agencies and federal agencies to look very closely at how this offender slipped through the cracks,” he said.

“How did this offender not come to the attention of state and federal agencies for more urgent action?”

Before his death, Monis was released on bail after being charged as an accessory to murder in the death of his ex-wife. He also faced dozens of indecent and sexual assault allegations.

“This offender was granted bail under the previous legislation, in fact two previous bail acts,” Hazzard said, adding he would not have been free if the new act was in force.

“It’s frustrating. It’s very frustrating for us. It’s frustrating for me as Attorney-General. It’s frustrating for the Premier, it’s frustrating for the entire government. It’s frustrating for the entire NSW community but we must accept the advice of our professionals,” he said.

“The professionals are absolutely adamant that January 28 is the earliest possible operational date for the legislation.”

The siege, which came to an end just after 2am on Tuesday morning when police stormed the Lindt Chocolate Cafe in a hail of gunfire, claimed the lives of two of the 17 hostages along with Monis.

The identities of the two hostages killed during the 16-hour-long siege at the cafe in Sydney’s Martin Place have been revealed to be barrister Katrina Dawson and Lindt Cafe manager, Tori Johnson.

At the time of the siege Monis was on bail, due to face court over two separate matters.

Last November he was charged with being an accessory before and after the fact to the murder of Noleen Hayson Pal, his ex-wife, who died in April 2013 in the stairwell of her Werrington apartment after being stabbed and set alight. His then girlfriend, Amirah Droudis was charged with murder.

He was bailed just over a year ago, on December 12, 2013 by Magistrate Daryl Pearce who said it was a “simple matter of fairness”.

Monis was also facing more than 40 sexual assault charges involving seven alleged victims. In March this year Monis was arrested and charged with the assault of a woman during a “spiritual healing” consultation in Wentworthville.

Before that Monis was charged with sending “grossly offensive” letters to the families of Australian soldiers killed in Afghanistan between 2007 and 2009. Monis was sentenced to 300 hours of community service and slapped with a two-year good behaviour bond.

He also approached the family of one soldier at the man’s funeral.

He regularly posted extensive rants against public figures. After Tony Abbott was elected in September 2013, Monis sent the prime minister a letter challenging him to a debate in which he said he would prove that “Australia and Australians will be attacked” as a result of the nation’s participation in the war in Afghanistan.

It has been claimed one of Monis’ demands during the siege on Monday was to have a discussion with Abbott.

Monis had been disowned by the Shia community, labelled as a fringe figure. In 2008 one of Australia’s senior Shia leaders, Kamal Mousselmani urged the federal police to investigate “Sheikh Haron”.

“We don’t know him and we have got nothing to do with him,” Sheikh Mousselmani said at the time. “The federal police should investigate who he is. It should be their responsibility.”

His website SheikHaron.com has been suspended, but featured the following statement earlier this week.

Islam is the religion of peace, that’s why Muslims fight against the oppression and terrorism of USA and its allies including UK and Australia. If we stay silent towards the criminals we cannot have a peaceful society. The more you fight with crime, the more peaceful you are. Islam wants peace on the Earth, that’s why Muslims want to stop terrorism of America and its allies. When you speak out against crime you have taken one step towards peace.

His former lawyer, Manny Conditsis described him as a “damaged goods individual that’s done something quite outrageous” with “nothing to lose”.

“With all that I know and what has occurred over the past year I’m not at all surprised because he is, or was, an extreme ideologue and there were many occassions where it was clear his thought process was so distorted by his passion for what he thought he wanted to achieve, or his perception of what he wanted to achieve, that anything like this could of happened,” Conditsis told ABC Radio earlier today.

“If you put that sort of an ideologue in that sort of a situation where he’s facing extremely serious criminal charges after having been in custody on remand, to use his terminology ‘tortured’ then from his point of view, I can certainly see that he may well of considered that he had nothing to lose.

“This is a damaged goods individual that has acted out of absolute desperation by committing this outrageous act.”

PHOTOS: A dramatic end to the Sydney cafe siege

VIDEO: The moment police stormed the cafe in the Sydney siege

CRITICAL INVESTIGATION: Police launch probe after three killed in Sydney siege

HOSTAGE TAKER: Man Monis was a ‘spiritual healer’ with a long rap sheet

HOW IT HAPPENED: Police entered when they heard gunshots inside the cafe

REACTION: The front pages of newspapers around the world this morning

BUSINESS AS USUAL: Sydney is open for business following the tragic event

SYDNEY TRANSPORT: What you need to know to head to the CBD today

PRIME MINISTER: There are ‘lessons to be learned’ from the Sydney siege

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