Suspected pirates caught by the Royal Navy could be transferred to Mauritius to face justice under a new deal.
Prime Minister David Cameron signed an agreement with his Mauritian counterpart Navin Ramgoolam which will allow suspects to be taken to the Indian Ocean island for prosecution.
Mr Cameron said the agreement was a sign that countries in the Indian Ocean were stepping up the fight against piracy.
The Government has already reached similar agreements with the Seychelles and Tanzania as part of the effort to tackle pirates from Somalia.
Mr Cameron said: "This is an important step forward following the London and Istanbul Conferences on Somalia this year and another sign that countries in the Indian Ocean region are stepping up their efforts against piracy.
"Piracy is a violent crime and pirates should be in no doubt that they will be arrested at sea, prosecuted in regional states and imprisoned."