East Timor's foreign minister Jose Ramos-Horta says the country's fledgling judicial and prison systems are frail because there are insufficient judges.

He has told Radio New Zealand that judges appointed by the United Nations two years ago were without basic education in law and only a few had law degrees.

Mr Ramos-Horta said the UN should have controlled the justice system until sufficient judges had been trained. Crowding in East Timor's jails has meant that lengthy prison terms are common for petty crimes.

East Timor became fully independent on May 20 this year, less than three years after holding a UN-supervised referendum in which voters overwhelmingly opted to break away from Indonesia.