HOUSTON (AP) — A Lebanese-born U.S. citizen who had been imprisoned in Dubai for more than four years on fraud charges is receiving medical treatment after being released on bond, but his exact whereabouts remain a mystery, his Ohio-based attorney said Wednesday.

Zack Shahin, who was arrested in 2008 on suspicions he embezzled millions of dollars while CEO of Deyaar Development, had recently launched a hunger strike in prison, threatening to strain relations between the United States and one of its top Persian Gulf allies. He was released last Thursday after claiming for months that he was being denied due process and was mistreated in jail.