A WELL-KNOWN architectural firm has sued three interior designers for breaching their employment contracts by moonlighting.

The defendants insist they were not employees but, instead, had gone into a profit-sharing business venture with Ong & Ong Architects, The Straits Times reported.

They are counter-claiming about $230,000, which they say is their share of the profits under the arrangement.

The case opened in the High Court yesterday, with the company?s chairman and director, Mr Ong Tze Boon, 39, as the first witness. Mr Ong is the second son of the late President Ong Teng Cheong, who founded the firm in 1972 with his wife Siew May.

The lawsuit is brought by Ong & Ong Architects and its interior design and landscaping arm, Ong & Ong.

The three-year relationship between the architectural firm and the defendants ? Mr Leslie Seow and Ms Rachel Yee, who were then partners at a small interior design firm, Six Planes & Partners (SPP), and Mr Ridzuan Sarbini ? started amicably, the court heard.

The relationship soured in 2006.

The plaintiffs want the court to declare that the trio had breached their duties as employees and are seeking an order to stop them from using confidential information. They are also seeking an account of the profits the trio have earned from the alleged moonlighting.

But the trio deny being employees of Ong Ong. Mr Seow and Ms Yee contend that under the business venture, they were not prohibited from doing work under SPP. In fact, they claim that the plaintiffs had breached an agreement to pay them half of the profits generated from interior design services. --my paper