A Sydney tradie who worked shoulder-to-shoulder with the alleged Bondi Beach gunman has revealed details about Naveed Akram’s disturbing behaviour.

Bricklayer Rishy supervised Akram for almost a year on the construction of the Crows Nest Metro station on Sydney's north shore and said they regularly had breakfast together.

He revealed Akram was a strange, quiet loner - with no real friends or social life - until one day when he suddenly erupted on the construction site and turned on a coworker.

Rishy believes he was the nearest Akram, 24, had to a real friend, and was stunned when images appeared of him allegedly opening fire on the Bondi Hanukkah festival.

Sixteen people died in the massacre, including Akram's gunman father Sajid, 50, with dozens more injured. Akram has now been charged with 15 murders among 59 charges.

Rishy is still struggling to take it all in, and revealed the eerie prediction his fellow tradies on the worksite made at the time.

'We talked about it,' he told the Daily Mail. 

'We had conversations about how Nav would be one of those guys you read about.'

Rishy said Akram told coworkers about his gun licence and said 'he was really proud of it'.

'That keeps me awake at night now,' he said. 

'Then one day when they were putting up scaffolding, one of the guys said something about God. I don't know exactly what was said but it wasn't good and Nav just lost it.

'He took heart and he just snapped at the guy yelling that you should never speak about a god like that.

'Everyone was shocked because the guy never really spoke.

'But just as quickly as he exploded, he calmed down as if nothing had even happened.'

Rishy remembers Akram initially being completely unremarkable. He was punctual, took pride in his work and largely kept to himself. 

He never spoke about his family, never mentioned weekend plans and rarely joined in casual conversations on site.

But as the months went on, Rishy said Akram began speaking with a noticeable stutter, refused to eat and would shut down completely whenever the crew discussed their dating lives.

'When I first met Nav in 2022 he was a pretty quiet kid, really polite - I remember thinking that kid is so respectful and has real manners,' Rishy said.

'He never ate at breakfast or lunch, didn't even drink water and would just sit there, arms folded watching us eat.

'He didn't scroll on his phone, just stared at me and I'd ask him, "Nav mate, aren't you hungry?", but he just said, "No", expressionless.

'There was one particular guy who spoke about women, intimate details of his weekends and Nav would just go quiet,' Rishy said. 

'Completely devoid of emotions, you could see the tension but he never said a word and just watched everyone as they chatted.'

After the blow-up with the co-worker, others refused to share a room with him when a contract came up in Newcastle that required them to stay overnight in an Airbnb.

'The boss asked the guy he had clashed with to share a twin room and he said no way,' he said.

'The worker that did end up sharing with him said he got up in the night to go to the bathroom and Nav was just sitting there, bolt upright praying.

'He wouldn't sleep and the guy was spooked. He'd say, "Nav, mate, it's 2am, get some sleep" - but he didn't.'

More than a week after the tragedy unfolded in Bondi, Rishy says he still cannot come to terms with the tragedy .

Authorities have since revealed ASIO had investigated Akram in 2019 for suspected extremist links to terrorist organisations.