An American businessman jailed for more than four years in Dubai under suspicion of corruption has started a hunger strike to push for a trial and seek greater U.S. diplomatic pressure in his case.

Zack Shahin, a former CEO of Dubai-based Deyaar Realty, is among dozens of prominent business figures and investors who have been placed under investigation for alleged financial irregularities in the United Arab Emirates, whose decade of astonishing growth was abruptly halted by a debt crisis and the global economic downturn more than three years ago.

But the Lebanese-born Shahin claims he has been left in legal limbo that shows no signs of ending. He said he began his hunger strike on Monday.

"I had to do something," he said Wednesday in a telephone interview from detention. "This is my cry for help. I'm asking the UAE government to give me my day in court and calling on my own government to be a better advocate for my interests."

Shahin was arrested in 2008 in probes over alleged embezzlement by executives at Deyaar. He was later the target of other investigations into alleged fiscal wrongdoing at the company, but no trial dates have been set.

Shahin, 52, denies any improprieties. His lawyers claim independent auditors found no evidence of fiscal abuses, but bail has been set at $5 million.

Also implicated in the Deyaar corruption probes was a former finance minister, Mohammed Kharbash, who was chairman on the company's board. He has denied any wrongdoing and has been granted bail.

Shahin's Washington-based legal team says American officials, including Secretary of State Hillary Rodham Clinton, have raised Shahin's case with UAE authorities, but have chosen to "tread lightly" to avoid disrupting Washington's close relationship with a key ally.

The spokesman for the U.S. Embassy in Abu Dhabi, Robert Arbuckle, said Thursday that American officials are aware of Shahin's hunger strike and "express concern about his condition." Shahin is among just a handful of Americans in long-term detention in the UAE.

The U.S. has "raised concern at all levels," said Arbuckle.

Arbuckle did not give further details of the U.S. discussions over Shahin, but noted that the delays in his case suggest "unequal treatment" compared with others accused of financial crimes in the United Arab Emirates.

UAE officials have not commented on the hunger strike.

"I'm either going to get my voice heard with the UAE legal system or die trying," said Shahin, who was raised in Ohio and whose wife now lives in Houston. "I don't want to die, but I'm already facing a slow death in prison without any trial date."

Local media have reported that a wave of hunger strikes has occurred in UAE prisons recently among inmates jailed on financial crimes, including issuing bad checks.