The families of five activists who again refused to appear in a United Arab Emirates court on Sunday on charges of insulting top officials have made a joint plea for their release. "We, the families of the five activists, who are held in prison over misdemeanour cases at the Higher Federal court... come forward with this petition to your most courteous selves after they had spent six months in imprisonment," said the statement received by AFP. "We turn to you asking for your interference, with your influence, in order to stop this trial that isn't consistent with international standards for fair trial, cancel the charges and order the release of the detainees," said the letter addressed to the president and vice president of the UAE and the crown prince of Abu Dhabi. The procedures and treatment of the detainees "before or during the trial, violated the standards of fair trial as internationally defined," said the statement. The violations include "their right to release pending trial... to be presumed innocent... to be tried without undue delay... (and) the right to appeal," said the statement. It also said that the procedures have violated "the international standards of right of the defence to question witnesses against the accused... (and) to prepare a defence." The defendants, alleging mistreatment, have refused to attend the hearings, drawing protests from prosecutors who accused them of "hampering the court's work." The next hearing is set for October 23. The families' plea said the detainees were denied "adequate medical care" and that some of them "were shackled with chains and handcuffs, and were not allowed to complain... They were occasionally deprived of being exposed to natural light, recreation time and exercise." Khalifa al-Nuaimi, a relative of one of the defendants, Nasser bin Gaith, wrote on his blog on Thursday that the head of the state security prosecution had visited the detainees in prison to monitor their situation. "According to news leaked from the prison, their cells were cleaned and medical files were opened for the five detainees," wrote Nuaimi. But "I have fears and concerns that these sudden actions taken by the prosecutors and the prison administration may be proactive measures to prepare for visits by local or foreign parties," he said. Bin Gaith's wife, Wedad al-Muhairi, told AFP her husband had already served more than six months in prison and called for his immediate release on the basis that if convicted, his sentence would be a period of three to six months. "The court has refused to release them on bail, although detainees shouldn't stay detained until the verdict," she said. Blogger Ahmed Mansoor and Bin Gaith, who lectures at the Abu Dhabi branch of the Sorbonne University, were detained in April along with activists Fahid Salim Dalk, Hassan Ali Khamis and Ahmed Abdul Khaleq. The men are accused of using the Internet to insult UAE leaders, call for boycotting last month's Federal National Council elections and for anti-government demonstrations. Sarah Leah Whitson, Middle East director at Human Rights Watch, said in a statement on Sunday that "the real insult to the Emirati government is not anything these men said, but the fact that the country’s leaders have jailed them for it." The UAE, a federation of seven emirates led by oil-rich Abu Dhabi, has not seen any of the widespread protests calling for reform that have swept other Arab countries, including fellow Gulf states Bahrain and Oman.