The human rights organisation Amnesty International’s secretariat in London has written a letter to Tripoli urging it to make known the location of two Swiss businessmen being held there.

The group have also asked the men be given access to medical help, lawyers and their families.

Amnesty says it believes it’s intervention can help. The group says Libya recently freed a group of opponents to the Kadhafi regime after it campaigned for their release.

So far, apologies by the Swiss government for the arrest of Hannibal Gaddafi, and a meeting with his father, Mummar Gaddafi have failed to gain the men’s freedom.

The two hostages were first forbidden to leave Libyan territory in July 2008. This September, Libya summoned the men for a medical visit.

The two men haven’t been heard from since.