AP DUBAI US OFFICIALS are “gravely concerned” about the health of a jailed American businessman who began a hunger strike more than two weeks ago over claims he has been left in legal limbo by the United Arab Emirates, a statement said on Thursday.

The US Embassy in Abu Dhabi also raised questions about whether Zack Shahin‚ who has been held for more than four years is being singled out for harsh treatment compared with other financial crime suspects in the UAE.

The US statements reflect Washington’s growing frustration with the handling of Shahin’s case and raise the possibility of a rare diplomatic tiff with the UAE, a close American ally and host of important US air bases and other strategic sites.

Shahin has been held in a Dubai prison for more than four years under suspicion of corruption, but no trial has been set. Shahin, 52, denies the allegations and began a hunger strike May 14 to demand that authorities address his case.

“We are gravely concerned about Mr Shahin’s health after more than two weeks on hunger strike,” the statement quotes US Consul General Justin Siberell as saying after he visited Shahin.

US officials have strongly urged the UAE to move ahead with Shahin’s case and review past court decisions that overturned an initial bail set at $135,000. Last week, a US envoy repeated Washington’s concerns to the UAE’s ambassador to the United States.