Season 4

Liz Hayes and Under Investigation's formidable experts investigate the strange death of a top SA cop in 1981. Written off as suicide for decades, compelling new revelations point to a sinister plot to kill the decorated detective.

In the 1980's and 90's, Sydney's gay community fell victim to ruthless bashings by savage gangs. Now, Under Investigation can reveal the role played by the NSW Police Force.

After over a dozen killings in 18 months, Sydney's gangland wars are getting bloodier. Under Investigation pulls back the curtain on the city's dark underbelly.

Between 1970 and 2018, 11 people have vanished or been murdered along the Flinders Highway, including missing backpacker Tony Jones. Under Investigation pieces together his final hours.

Travellers onboard cruise ships have seen violent crime, pollution, and now a COVID crisis. Liz Hayes and a panel of experts examine whether it has learnt from past lessons.

Nearly 50 years ago, 11-year-old Joanne Ratcliffe and 4-year-old Kirste Gordon were snatched from the Adelaide Oval. Groundbreaking new technology helps identify their kidnapper and reveal a shocking twist.

Uncover the terrifying abuse faced by young, vulnerable women at the hands of the Esther Foundation, a Perth cult once backed by some of the most powerful leaders in the country.

After government inspectors found a slug in a Melbourne catering company's factory, a public health warning erupted into a bitter brawl between a David and a Goliath.