Castle will focus on commercial litigation and corporate/commercial matters (including trade practices), providing advice for a number of clients including Competitive Foods (which franchise Hungry Jack's stores as independent businesses).

In his most recent role at ASIC, Castle led the Storm Financial investigation team through its primary investigation phase, starting with the winding up of Storm in March 2009. He was also a key executive involved in planning for the implementation of ASIC's new credit jurisdiction in July this year.

Castle practised at Seven Wentworth Barristers' Chambers up until 2007, specialising in major commercial and trade practices cases, including appearances for Telstra in Seven's C7 litigation and Competitive Foods in its franchise rights defence and $75 million damages award against Burger King.