Two Tongan MPs, including the Minister of Internal Affairs, are due to appear in court on separate charges on 26 March.
Internal Affairs Minister 'Akosita Lavulavu and her husband 'Etuate were arrested and charged with dealing with forged documents and obtaining by false pretences this month.
Matangi Tonga reports the charges relate to a number of irregularities in the 2016 audit of the 'Unuaki 'o Tonga Royal Institute, which the couple established.
Also due to appear in the Magistrates Court on the same day is the former prime minister and parliamentary speaker, Lord Tu'ivakano.
Tu'ivakano was arrested at the beginning of the month and charged with making a false statement for the purpose of obtaining a Tongan passport, perjury, acceptance of bribery and money laundering.