The UAE has paid $10m to settle a torture case after an American arms dealer alleged that he was abducted, taken to a secret location, tortured and forced to sign a false confession when he was working in the United Arab Emirates.

The man, named Khaled al-Hassen, was allegedly tortured by Mohammed bin Zayed al-Nahyan, crown prince of Abu Dhabi, during the 1980s.

The suit alleged that bin Zayed, his brother and president of the UAE, Khalifa bin Zayed al-Nahyan, and General Saeed Hilal Abdullah al-Darmaki, at one time the minister for interior affairs, were among the torturers.

The Middle East Eye reported that it had obtained emails which cover the period from May 10, 2010 to March 6, 2014, revealing correspondence between Yousef al-Otaiba, the Emirati ambassador to the US, and Paul Hastings, a Washington legal firm hired to defend the three men.

In 2013, Hassen and his lawyers agreed on a settlement of $10m, to be delivered to five separate accounts.

Hassen was hired around 1981 by Emirate royals to start a marketing firm. The company represented big US companies including Beech Aircraft, ITT, Raytheon, General Dynamics and Bell Helicopters.

When in prison, Hassan was told that if he ever talked about what had happened to him “you will never see your family again”.