British-Thai royal artist Chulachak "Hugo" Chakrabongse has been fined $15,000 (about 450,000 baht) for using a mononym already trademarked by a US artist, reports said on Tuesday.

Hugo, a Thai celebrity, collaborated with several one-name US artists such as Beyonce and Jay-Z. He attained international stardom after he released the Old Tyme Religion album on the Roc Nation label. The album hit the best-seller charts with singles including 99 Problems and Bread and Butter.

A New York-based artist named Jon Hugo Ungar filed a lawsuit against Chulachak at the US District Court in California on April 17 last year. The American claimed he had performed as "Hugo" for more than 10 years, and that he received a trademark for the name on Dec 10, 2010.

The US Hugo managed to sell only 3,000 copies of his CD. But he complained to the court that the Thai Hugo had caused confusion in the marketplace. Organisers often put up the wrong information, and linked fans to websites of the wrong Hugo.

Mr Chulachak said that Mr Ungar initially filed a demand for compensation of US$500,000, about 15 million baht. Roc Nation did not act at first, thinking that it was not a serious suit, but Unga then took the issue to court.

"The final verdict was that I was fined $15,000. I did not appeal because the cost for the process would be equivalent to the fine. So far, the label has agreed to pay the fee because I currently don't have the cash,” the Thai Hugo said.

Mr Chulachak told the media that neither he nor Roc Nation had checked the name "Hugo" thoroughly before releasing his album.