A divorced couple have been handed hefty financial penalties over unauthorised share trading in 2007.

At the time, Mr Wang Boon Heng was an undischarged bankrupt and used trading accounts set up in the name of his former wife, Ms Foo Jee Chin, to trade. He also used accounts in another person's name.

Undischarged bankrupts are not permitted to open share trading accounts in Singapore.

The State Court of Singapore imposed a $75,000 penalty on Mr Wang and a $50,000 penalty on Ms Foo. The civil penalty action was launched by the Monetary Authority of Singapore (MAS) in 2013.

They will also pay $58,636.23 in total for legal and other costs incurred by the MAS after the Singapore Exchange referred the case to the central bank.

Mr Wang carried out the trading using accounts in Ms Foo's name with DMG & Partners and UOB Kay Hian between September and December 2007.

This was deemed a breach of the Securities and Futures Act, Section 201(b) as the brokerage firms did not authorise or give consent to Mr Wang's actions.

By allowing Mr Wang to trade using her accounts without the brokerage firms' okay, Ms Foo was deemed to have intentionally deceived the firms.

Mr Wang also traded using accounts opened in the name of a second person in 2007. This person has been issued a warning letter.

"This civil penalty action reflects MAS' firm stance against unauthorised trading, which is a deception against broking firms that are unaware of the beneficial owner behind the trades," MAS assistant managing director for capital markets Lee Boon Ngiap said yesterday. "Such behaviours carry regulatory risks as perpetrators of insider trading and market manipulation often hide behind nominee accounts."