Libya may take further measures against Switzerland if it fails to apologise for the detention of a son of Moammar Gaddafi in Geneva last summer.

The Libyan deputy minister for European affairs, Abdelati al-Obeidi, told a media conference on Thursday that his country wanted "to defend the rights of its citizens".

In addition to an apology Libya is also calling for the officials responsible for the arrest of Hannibal Gaddafi and his wife to be punished, Obeidi said.

Geneva police detained the couple in July after receiving allegations that they had seriously mistreated two of their servants.

The couple, who were in Switzerland for the birth of their child, were released after two days and left the country. Charges against them were dropped in September after the servants withdrew their complaint, having reached a financial arrangement with Hannibal.

The Libyan foreign ministry said on Thursday that an independent joint committee set up to investigate the case had concluded that the arrest was illegal, but the Swiss side was attempting paper over the truth in order to save the face of the authorities.

Since the summer Libya has taken a number of steps against Switzerland and Swiss nationals. Last week it told Swiss International Air Lines it could no longer fly to Tripoli "for technical reasons".

Since the row erupted the Swiss foreign ministry has been conducting talks with Libya in an attempt to find an agreement, but few details have emerged.

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