A Melbourne law firm could face investigation after dozens of confidential files were found dumped in an unsecured recycling bin in the CBD.

The bin was overflowing with private documents including medical reports, a police record-of-interview, copies of cheques, income tax statements, land title records and settlement deeds from lawsuits.

The unlocked bin fllled with confidential documents left on the street in Melbourne's legal precinct. Credit:Chris Vedelago

There were also transcripts of audio recordings of a meeting involving senior executives of a former trade union.

A former union official was facing disciplinary action after allegedly stealing cassette tapes that contained recordings of branch committee meetings.