Amnesty International is calling on the Libyan authorities to immediately reveal the whereabouts of four men - including two British nationals - who are being held in secret after being arrested in the country and taken away by security officials more than two weeks ago.

The men - British brothers Zeyad Ramadan and Ghazi Ramadan, and Khaled Sury and another unnamed man - were arrested in a western district of the capital Tripoli on 19 March.

According to relatives who live outside Libya, at about 8pm on 19 March a group of men - believed to be Internal Security Agency officials - broke down the door of the house where Zeyad and Ghazi Ramadan were living. They were arrested, along with their two guests - father of four Khaled Sury and another unnamed man. After the arrest the security officials reportedly remained at the property for several hours, searching and confiscating a number of items including computers and documents.

The Ramadan brothers have been in Libya since late December 2010 working at a software company. It is unclear why the two men along with their guests, also businessmen, were arrested as they had no political affiliations and no role in anti-government protests according to their relatives.

Since the arrest some of their relatives in Tripoli have made inquiries regarding their whereabouts, but have not been able to confirm where they are being held or for what reason. The men are held incommunicado and are at risk of being tortured. Amnesty supporters are pressing the Libyan authorities, including via the Libyan interests bureau in London, for action on the men’s case.

Amnesty International UK Director Kate Allen said:

“We’re very worried for these four men and it’s disturbing that this amount of time has passed without word of their whereabouts.

“The Libyan authorities should reveal the men’s location and either immediately release them or charge them with a proper criminal offence.”

Many people have been subjected to enforced disappearance by forces loyal to Colonel Mu’ammar al-Gaddafi since the current unrest in Libya began in mid-February. These include dozens who were arrested and detained in eastern Libya and are believed to have been transferred to the Tripoli area controlled by al-Gaddafi forces. Others have disappeared in Tripoli or other areas controlled by Colonel Mu’ammar al-Gaddafi.

Amnesty recently published a report detailing the cases of over 30 individuals who have “disappeared” in Libya since before protests began, including political activists and those suspected of being rebel fighters or supporters of fighters. The cases documented are believed to represent only a small proportion of the total number of people who have been detained or have disappeared in the custody of Colonel al-Gaddafi’s forces in recent weeks.