WASHINGTON (AP)  As a trusted adviser to a member of the ruling family of the United Arab Emirates, Texas businessman Bassam Nabulsi says he safeguarded the sheik's most important documents: financial records, investment documents, and videotapes showing the sheik torturing people with a cattle prod and a spiked plank. When the business relationship began to deteriorate, Nabulsi says, he also was imprisoned for months and tortured by jailers trying to get the tapes back. Now, the tapes could become evidence in a federal lawsuit against Sheik Issa Bin Zayed Al Nahyan, a son of the late UAE president and brother of Abu Dhabi's crown prince. By custom, a member of the Al Nahyan royal family serves as president of the UAE. The lawsuit and the tapes could prove embarrassing to the UAE, a U.S. ally that promotes itself as a pro-Western nation catering to business travelers and tourists. The tapes have not been made public but The Associated Press viewed 11 still frames from one of the videos. They showed a man who appeared to be Sheik Issa beating another man with lumber, firing an automatic weapon into the sand around him and forcing an apparent cattle prod into his anus. The victim also appeared to have been partly run over by a SUV and had salt poured on his wounds. Lawyers said the video also showed the victim's genitals being lit on fire. They said the abuse began because the sheik felt he had been overcharged in a grain deal. "Ultimately this video, or certainly large portions of it, will be played in court," said Anthony G. Buzbee, who represents Nabulsi in his lawsuit. The UAE Embassy in Washington released a brief statement Monday, saying it was aware of the lawsuit but that, since the government itself was not being sued, it would not comment on the accusations. Nabulsi is suing for millions he says he is owed for various business deals. He also charges Sheik Issa and other members of the royal family with false imprisonment and with torturing him. Buzbee says he has three other torture videos. If he prevails, his lawyers said they would try to seize Issa's U.S. assets, which could include portions of the Abu Dhabi Investment Authority, which is the largest sovereign wealth fund in the world and has an estimated $875 billion in assets. Last year it invested $7.5 billion in Citigroup. The lawsuit has been languishing in a Houston federal court for nearly two years as attorneys tried to serve Issa and others with court papers. Efforts to deliver the documents to the royal family through UAE lawyers have failed and a confirmation of mail delivery was returned unsigned, according to court records. A federal judge gave Nabulsi's lawyers until the end of the month to try again and, if unsuccessful, explain why the case should not be dismissed. The lawyers filed an amended lawsuit Monday describing the videos in greater detail. Nabulsi worked for years making arrangements for Arab investors and dignitaries who traveled to Houston seeking medical care. According to the lawsuit, Sheik Issa recruited him to work as his personal business manager. "As the Sheikh's moods grew darker, he began a habit and custom of torturing his employees and anyone else with whom he disapproved," the lawsuit claims. "As his degeneracy increased, Sheikh Issa began to have such torture sessions taped, so he could enjoy viewing them later." The torture sessions became a wedge in the business and, when it became clear the relationship were falling apart, Sheik Issa allegedly had Nabulsi arrested on marijuana charges. He was ultimately acquitted of those charges but the lawsuit says Nabulsi was interrogated about the videotapes while being held for more than three months. "He was told daily that his wife would be raped, his children would be killed, that he would be killed," Buzbee said. His original lawsuit sought more than $1 billion but the amended lawsuit filed Monday does not seek a specific amount. Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more