Former Auburn deputy mayor Salim Mehajer has shown up at a Sydney court for a civil hearing a week after he was injured in a car crash on his way to court.

Mehajer was involved in a crash last Monday on his way to court for the first of two hearings over alleged assaults, with his solicitor later producing a medical certificate to have the matters adjourned until early 2018.

The certificate covered Mehajer until October 24, but the 31-year-old was at Sydney Local Court on Tuesday concerning a civil dispute over a property sale that went awry.

Mehajer had been told that if he didn't appear the defence would be struck out, according to court documents.