Senior CFMEU figures secretly helped organised crime kingpin George Alex build a sprawling and corrupt labour hire empire, despite repeated warnings he was an underworld figure who had previously bribed union officials and ripped off both workers and the Tax Office.

The extent of Alex’s corrupt dealings with the CFMEU can be laid bare after he was convicted on Tuesday of tax evasion and money laundering as part of an illegal scheme that federal police found relied on Alex’s success “leveraging contacts in the trade unions” and inside large building companies.