The Swiss government has authorized prosecutors to open criminal proceedings against Libya for allegedly taking two Swiss men hostage following the 2008 arrest in Switzerland of Moammar Gadhafi's son.

Switzerland also accuses "persons unknown" in the Libyan government of blackmail for detaining Max Goeldi and Rachid Hamdani for over a year.

They were detained in Tripoli on immigration charges weeks after Hannibal Gadhafi was arrested by Geneva police for allegedly mistreating his servants.

The case threatened European ties with the oil-rich North African country until Switzerland agreed to apologize, pay Hannibal $1.5 million and submit to an international dispute settlement tribunal.

The Swiss Justice Ministry couldn't immediately say Monday why Switzerland had decided to prosecute Libya now.