The inquest has heard that the gun used by Monis in the siege was "almost certainly recently obtained". 

2.53pm: Gun used in Martin Place siege was "almost certainly recently obtained"

The inquest has heard that the gun used by Monis in the siege was "almost certainly recently obtained". No gun was found when police executed a number of search warrants, the most recent of which was around a year before the siege. Just how long he had been planning the incident "remains to be assessed" the inquest has heard. 

2.35pm: By 2013 Gunman's life was "spiraling".

Counsel assisting Jeremy Gormly says that by late 2013 Monis' life was deteriorating.

"When he arrived in Australia he expetced to make a mark," he says. But he was a "man spiraling downwards".

By 2014 Monis had no money, he was in debt, he had no employment skills. "His attempts to develop a religious following failed," Mr Gormly says.

2.22pm: Siege gunman sought membership of Rebels motorcycle club

The inquest has resumed after a one-hour lunch break with revelations that in 2013 Man Monis actively sought to become involved with the Rebels Motorcycle gang.

He spoke to members of the Rebels' chapters at Mt Druitt and Ingelburn and sought to become a member.

Members of the club have declined to give evidence at the inquest, however, one member told investigators "no one in the club really liked him" and that they thought he was "weird". 

2.14pm: Gunman became increasingly radical from 2006

On November 21, 2006, Monis changed his name from Mohammad Hayson Mavros to Man Haron Monis. Haron is the name of Moses' brother. Soon after changing his name, Monis he created a website sheikharon.com under which he posted increasingly readical, extreme commentary and videos about western governments, including that of Australia. It was around this time that he began sending offensive letters to the families of Australian soldiers who had died in Afghanistan, telling them, among other things, that their loved one had died while fighting in an unjust war.   

12:46pm: Monis became obsessed with Australian customs officers

In 2004 Monis appears to have become obsessed with Australian customs officers, the inquest has heard, making repeated complaints both about the officers being strict and discriminatory, but also about the officers being too lax. "In one instance, Mr Monis caught a plane to NewZealand and returned immediately on the next flight for the sole purpose, it seems, of demonstrating unreasonable behaviour by Customs officers," counsel assisting, Ms Callan said.

12:34pm: The inquest has heard that the evidence of Monis' sexual and indecent assaults on women was strong, including similar accounts from multuple women from different parts of Sydney and different ethnic and cultural backgrounds. The inquest has heard that Monis allegedly would pretend to be "healing" the women, using a paint brush to paint their bodies with water from a bowl and then moving on to more serious assaults. 

12.46pm:  Monis set up "spiritual healing" businesses targeting "vulnerable women"

In 2001 Monis set up the first of a number of "spiritual healing" businesses, the first of which was under the business name "Spiritual Power". The inquest has heard that it was these businesses which Monis later allegedly used to sexually and indecent assault vulnerable women. These businesses were "aiming generally at poorly educated impressionable people particularly women, who would seek such services including those who believed in black magic or that they were cursed," Ms Callan said. They were "vulnerable women with troubles in their lives," she said.

How Monis progressed from Iranian student of Islam to a shotgun-wielding extremist is the focus of the first stage of the coronial inquest which began in Sydney on Monday.

Counsel assisting, Jeremy Gormly SC, told the court a psychologist and psychiatrist who treated Monis for mental health complaints as recently as 2011 would be among more than 100 witnesses who will give evidence at the inquest.

But while Monis ‘‘unquestionably’’ had some mental health issues they appeared to be modest, Mr Gormly said.‘‘Mental illness may not provide a full answer to the questions about his motivations for the siege,’’ he said.

Coroner Michael Barnes said the first stage of the inquest, covering two weeks, will look deeply into Monis’s background to identify how he was diverted ‘‘down such a dangerous pathway’’.

‘‘Was Monis a so-called lone wolf prosecuting an Isis-inspired terrorist act or was he a deranged individual pursuing some personal, private grievance in a public manner?’’ Mr Barnes said.

Security is extremely high at the inquest, one of the most high profile to be held within the NSW courts system.

Authorities are dealing with the extra sensitivities to protect the families of victims Tori Johnson and Katrina Dawson as well as hostages who will be called to give evidence about the events of December 15 and 16, 2014.

Mr Barnes said the public airing of details of the siege could be painful but the investigation was critical.‘‘Speed is of the essence,’’ he said.

‘‘It would be unforgivable if we delayed and another incident were to occur before we had learned the lessons of the last.

‘‘This is not a normal investigation. It is grappling with questions of national significance.’’

Mr Gormly said evidence of how Monis was monitored by national security agencies would be heard but, in order to protect public safety, that evidence may be heard in a closed court and some findings would not be made public.

Extensive evidence has been gathered about Monis, dating back to his Iranian high school report and grainy video footage of his graduating as a minor Islamic cleric.

Experts from the UK are among those consulted by investigators, the court has heard.

The court also heard Monis’s partner, Amirah Droudis, was granted leave to give evidence but had since withdrawn.

10.45am: The Sydney siege inquest will probe gunman Man Haron Monis’s background to understand if he was an ISIS-inspired terrorist or a ‘‘deranged individual’’ seeking to deal with a private grievance in the most public way possible.

There was tight security and early morning queues outside John Maddison Tower, in Sydney’s CBD, where a fortnight of hearings was launched on Monday.

Coroner Michael Barnes said the first tranche of evidence would centre on the hostage-taker, five months after he took 18 people hostage in the Lindt Cafe on December 15.

‘‘We will look deeply into his background, in an endeavour to identify how he was diverted down such a dangerous pathway,’’ Mr Barnes said.

One issue was whether Monis was a ‘‘lone wolf’’ inspired by overseas terrorist groups to act out an attack on Australian soil.

Some had questioned the decision to push forward with an inquest so soon after the deaths of Tori Johnson and Katrina Dawson, who were both killed in the final moments of the 17-hour crisis.

‘‘Inevitably, these hearings can add to the pain of some of those directly impacted by the despicable actions of Mr Monis,’’ Mr Barnes said.

But it would’ve been ‘‘unforgivable’’ if the inquest had been delayed and a similar atrocity had occurred.‘‘

Pursuit of answers can’t be delayed. Shortcuts can’t be taken,’’ Mr Barnes said.

For national security reasons, Mr Barnes said the court would be closed during some evidence.

Monis’s partner Amirah Droudis had initially wanted to give evidence at the inquest but had since withdrawn, the court heard.

Droudis was in November 2013 charged with the murder of Monis’s former de-facto partner and mother-of-two Noleen Hayson Pal.

10.30am: A coronial inquest into the Sydney Lindt Cafe siege is due to resume.

A two-week session of hearings from Monday will begin a comprehensive inquiry into the deaths of victims Tori Johnson and Katrina Dawson during the siege, which started on the morning of December 15, 2014.

Coroner Michael Barnes will also examine the death of gunman Man Haron Monis, what was known of him as a security risk and how the siege was managed by police.

Apart from detailing what happened during the 17-hour ordeal and whether it could have been prevented, the inquest will consider whether the siege was an act of terrorism and implications it has for citizens going about their daily lives.

Large numbers of witnesses, including hostages, are expected to be called to give evidence over the course of the inquiry.

More to come.

AAP and SMH