A first-home buyer is suing Sydney property developer Selim Mehajer, alleging he staged “the biggest scam against ordinary people in Auburn’s history”.

Jason Tran, 31, is suing for compensation in a local court civil claim after purchasing an off-the-plan unit from Mr Mehajer’s company The Sydney Project Group in April 2014.

Court documents revealed Mr Tran purchased the abode in Sky Point Towers, on John Street, for $635,000.

He alleged that soon after he paid his deposit, he learned that work on the building had not started and that Mr Mehajer had applied to Auburn Council to change the size of the building, reducing the 106-square-metre unit to 76 square metres.

Mr Tran said in August 2015, he was called in by his conveyancer who said the original plans had been changed and it affected everyone buying in the block.

He alleged he was told that his unit had been reduced so significantly that it “no longer existed in the plan”.

‘Scam against ordinary people’

In the court papers Mr Tran stated: “I feel sorry for all the other purchasers who have been affected by what I believe from my experience with this purchase is the biggest sting or scam against ordinary people in Auburns history.”

He said he thought Mr Mahajer stood to make a profit increase of $45 million by changing the plans.

Mr Tran is suing for damages of $80,000, plus costs. Mr Mehajer is arguing that he has done nothing wrong because the deposit was refunded on February 19, 2016.

In court papers he stated that it was up to Mr Tran to apply to the government to get the stamp duty he paid back.

“I am not aware of any circumstances that would entitle the plaintiff to aggravated damages,” he said in the statement.

Mr Mahajer came to court on Tuesday unassisted after being injured in a recent car crash going to a separate court matter on assault charges.

The former Auburn Deputy mayor is also facing electoral fraud charges, with that case resuming in December.

-ABC