Slain university student Jamie Gao faced court on kidnapping and assault charges a week before he was allegedly shot dead by two former detectives during a botched multimillion-dollar drug deal.

The murky past of the 20-year-old business student can be revealed as disgraced former detectives Roger Rogerson and Glen McNamara are behind bars charged with his murder.

Two days after his body was found wrapped in a blue tarpaulin off the coast at Cronulla, his girlfriend visited the site on Wednesday and threw flowers into the ocean near where her ''babe'' was discovered.

Friends said they were in ''absolute shock'' that the credit-average student, who came from a good family, had been murdered.