Controversial former deputy mayor Salim Mehajer has been disqualified from managing corporations for three years, "as a means of protecting others from his incompetence," the Australian Securities and Investments Commission has announced.

ASIC's decision to disqualify Mr Mehajer in November 2015 was upheld by the Administrative Appeals Tribunal (AAT) in late August, which found his management of corporations SMPD P/L and SMEC P/L "fell far short of what is reasonably expected of a director."

The announcement may shed some light on a cryptic social media post from the colourful Sydney identity on Saturday (since deleted), suggesting that he was leaving Australia.

In the post on his Instagram page, Mr Mehajer included a picture of a ship on Sydney Harbour with the caption, "Goodbye Australia".