Senior figures in the Victoria Police task force tackling the Big Build corruption said there was “no doubt” organised crime had infiltrated the construction program.

Investigative journalist Nick McKenzie told 3AW Breakfast hosts Jimmy Bartel and Mark Allen it had been challenging to build evidence against gangland figures due to fears of safety from potential witnesses.

Press PLAY to hear what McKenzie thinks the turning point is

“To testify against people in the gangland, you take that risk. Your house will be firebombed, your business will be affected, your personal safety, or that of your family, may be affected,” he said.

Images: @Victoria’s Big Build/Facebook, Nine