It was Man Haron Monis's refusal to have his picture taken or answer basic personal questions that first raised the suspicions of his girlfriend's relatives.

"Things like 'what do you do for work?, 'where is your office?' - basic questions for normal people,"  said the cousin of Monis's  girlfriend, neither of whom can be named.

"We said 'is there something wrong with this guy? He's not letting us take any photos - is he hiding something?'"

The inquest into the Lindt cafe siege heard on Wednesday that the relatives became so concerned that in 2010 they decided to call the Australian government's national security hotline.

"My sister rang ... [because] we wanted to see if he was listed," the cousin said.

"She was advised that he wasn't a threat because he hadn't had any overseas contact."

Four years later Monis held 18 people hostage in the cafe, causing the deaths of two of them.

Earlier, the woman described how when she first met Monis at a family function, he had told them his name was "Michael", a 39-year-old from Egypt.

"The introduction was very awkward when we first met because he was Muslim ... he was the first Muslim man to be introduced to our family."

"He was very quiet, very well-mannered ... attentive to the children."

However, it became increasingly clear that Monis and his girlfriend were falling in love.

"We had no doubt that my cousin was madly in love with this man," the woman said.

"They were kissing, hugging. We had no doubt."

The inquest heard that Monis went to great lengths to avoid having his photo taken, wearing a baseball cap on special occasions such as Christmas to hide his face.

His girlfriend would intervene when questions became "too personal" telling her relatives "next topic" or "respect his privacy".

The inquest heard that Monis's girlfriend had a falling-out with her relatives after he was charged with sending offensive letters to the families of Australian soldiers who died in Afghanistan, and that they had little contact with either of them in the months leading up to the siege.

Earlier, the inquest heard from Monis's barber, Anthony Hancock, who shaved the gunman's head twice a week from 2002 until 2005.

"It took him six or seven months to tell me what he was doing for a living," Mr Hancock said.

"Eventually he told me he was a clairvoyant. He was very secretive, he didn't really talk that much."

Despite his secrecy, in 2005 Monis asked Mr Hancock to start coming to his clairvoyant studio to shave his head.

"It was set up like an office with a desk, phone, lounge and a big screen TV," the barber recalled.

"There was a camera on a tripod and roughly four or five other cameras. I asked him 'why's there so many cameras?' and he said 'I film many of the sessions'. He said he did white magic and spells - only good magic."

The inquest continues.