Bahrain has released four Britons held in the country for 18 months after the banks they worked for collapsed, in a meltdown that has caused a multi-billion dollar row between two Saudi families.

The four - who worked at banks related to the empires of businessman Maan Al-Sanea and the Algosaibi family he is now in conflict with - all returned from Bahrain this week, sources close to the matter told Reuters.

The men had been ordered not to leave the small island nation off the coast of Saudi Arabia, pending investigations after Awal Bank and The International Banking Corporation (TIBC) were put into administration in the middle of 2009.

But no formal accusations were ever levelled against the four - Tony James, Alistair MacLeod and Cliff Giddings, all formerly senior executives at Awal Bank, and Kevin Moriarty, who was at TIBC.

The failure of the banks is a centrepiece in a spectacular row that has erupted between the Ahmad Ahab Algosaibi and Brothers (AHAB) business empire and Al-Sanea, who is related by marriage to the family, but runs his own Saad Group.

The Algosaibi family have accused Al-Sanea of defrauding them of billions of dollars, in court cases in New York, the Cayman Islands and London. The Saad Group, Maan Al-Sanea and his wife, Sana Algosaibi, deny the accusations.-Reuters