DUBAI, May 23 (Reuters) - Two former senior officials of the Ras al-Khaimah Investment Authority (RAKIA) in the United Arab Emirates (UAE) have been sentenced in absentia to 15 years in prison for embezzlement, according to court documents released on Tuesday.

Khater Massaad and Gela Mikadze were sentenced on April 26 by a court in Ras al-Khaimah (RAK) for defrauding RAKIA of $17.2 million in 2011. A third man, George Janashia, was also sentenced to 15 years in prison in absentia.

Mikadze and Janashia, both citizens of the former Soviet republic of Georgia, were ordered to repay $12.8 million and $4.4 million respectively. The three defendants were also fined $17.2 million, according to the documents which were released by the RAK government.

A spokesman for Massaad's legal team said Massaad strongly denied the "trumped up charges", which relate to the 2011 sale of Georgia's Poti Sea Port and are part of a wider corruption case against Massaad, a former chief executive of RAKIA.

"No evidence has ever been presented to him or any of his legal representatives," the spokesman said.

State body RAKIA aims to foster development in Ras al-Khaimah, one of the poorer parts of the UAE. It has also made overseas investments in the past, although this activity has ceased in recent years.

Mikadze, the former general manager of RAKIA's Georgia division and now a member of Georgia's parliament, said the verdict was "unprecedented and outrageous."

"I have not even been informed about the trial," Mikadze told journalists in the Georgian capital Tbilisi.

"This decision has been made just by one judge in a small room behind closed doors, and it's unprecedented," he said. He declined to elaborate on the case details.

Janashia's whereabouts are unknown.

The court documents stated that Massaad knowingly entered RAKIA into an agreement with a company controlled by Mikadze and Janashia that RAKIA would later be forced to break. It then had to pay the firm $17.2 million in compensation in order to sell the port.

Massaad has insisted that the charges brought by the RAK government are unfounded, and that an October 2015 trial at which he was convicted in absentia by an RAK court of corruption and fraud had numerous flaws.

Massaad was detained in Saudi Arabia last year under an arrest warrant issued by the government of Ras Al Khaimah. Massaad ran RAKIA from 2007 until 2012. He was also behind the establishment of RAK Ceramics -- the emirate's most prominent company and one of the world's largest makers of porcelain goods.

(Reporting by Alexander Cornwell and Sami Aboudi; Additional reporting by Margarita Antidze in Tbilisi; Editing by Catherine Evans) ((Alexander.Cornwell@thomsonreuters.com;))