Sentenced to nine months' jail in 2013 for storing more than 307 cartons of contraband cigarettes, Tan Hock Chwee also had cash, a luxury watch and bank deposits confiscated from him then.

Now, the 68-year-old has been issued a confiscation order for more than $1.5 million by the High Court after a further probe - $800,000 of which had been used to buy a terrace house, and the rest coming from the increase in value of the house.

After Tan was sentenced in 2013, the Commercial Affairs Department (CAD) found that he had "significant wealth that could not be satisfactorily accounted for".

In a joint statement with the police and Singapore Customs, the CAD said it established that Tan had accumulated $875,288.70 of unexplained wealth between Jan 1, 2009, and July 25, 2012. He used part of this to buy a terrace house in 2010 which subsequently experienced a capital gain of around $700,000.

"This capital gain is also regarded as part of Tan's benefits from criminal conduct," said the agencies.

Anyone who is convicted of a serious offence under the Second Schedule of the Corruption, Drug Trafficking and Other Serious Crimes (Confiscation of Benefits) Act can have the benefits derived by him from criminal conduct confiscated.