SINGAPORE, April 11 -- A restaurant in Singapore's Chinatown has reportedly denied responsibility for a notice claiming it would impose a 104 per cent surcharge on American diners, calling it a "malicious prank".

The Straits Times cited a staff of Xie Lao Song restaurant on Pagoda Street saying it investigating the incident and has not ruled out lodging a police report but declined to provide further details.

"We've been open for over a decade. We would never do something so crass," a worker who wished to remain anonymous told the paper.

The handwritten signs, which appeared at the restaurant's entrance stated that Americans would be subject to the surcharge starting April 9, in apparent reference to a newly announced US tariff on Chin...