RIVERHEAD - The CEO of a Hauppauge-based company was arraigned today on charges of grand larceny and scheming to defraud for allegedly stealing from his employees' retirement savings plan.

Om Soni, the head of Sonix Medical Resources, is accused of failing to put employee contributions into the company's 401(k) plan like he promised.

The company was also supposed to match the contribution. Instead, officials say Soni used the money, which amounted to $278,000, to run his company and bankroll his lavish lifestyle.

Suffolk District Attorney Thomas Spota says Soni, of Oyster Bay, bought a multimillion-dollar mansion in Upper Brookville and several limited-edition luxury cars, including a Bentley and a Lamborghini.

"The money was going into his personal piggy bank," he says.

According to investigators, from 2007 to 2009, Soni encouraged his employees to invest in the company's 401(k) plan. However, in 2008, Soni's alleged scheme started to unravel when some of his workers noticed that no contributions were being made to their plans and contacted the Department of Labor.

Soni's company has since gone out of business. Now, Spota wants Soni to pay back all the money to his employees. If convicted, he could face up to 15 years in prison.