Nicola Gobbo’s diary notes suggest police threatened to expose a drug charge from her university days and ruin her legal career unless she started working for them.

A royal commission heard on Wednesday that officers pressured Ms Gobbo, then a young solicitor, over information on her employer, who they believed was laundering money.

The commission is investigating the conduct of Victoria Police and one of their most prized informers, gangland barrister turned supergrass Nicola Gobbo, also known as Lawyer X and Informer 3838.

Ms Gobbo first became an informer in 1995 when she tried to set up her boyfriend in a drug sting after she was nabbed for possession as a law student.