Former deputy premier Andrew Stoner breached the ministerial code of conduct by failing to seek ethical advice before taking a job at an investment bank that he had dealings with as minister for trade and investment.

The revelation has prompted a call for Premier Mike Baird to refer Mr Stoner to the Independent Commission Against Corruption for investigation of the breach.

Premier Mike Baird with Mr Stoner when he announced he would leave Parliament. Credit:Dominic Lorrimer

Mr Stoner, who quit politics at the March 28 election for family reasons, has taken a role as "senior adviser" to investment bank Moelis Australia, with whom he had dealings while in office in relation to a visa program aimed at wealthy Chinese investors.

The Significant Investment Visa was announced in 2012 by then federal Labor immigration minister Chris Bowen.