Tonga's former transport minister Paul Karalus and current Prime Minister Fred Sevele will appear before the Royal Commission into the sinking of the Princess Ashika ferry later this month.
The commission into last year's accident, in which 74 people died, is now in recess.
During the last sitting of the inquiry it emerged another inter-island ferry - the Pulupaki - has continued to operate despite being declared unseaworthy.
Evidence was submitted to the commission that showed the Tongan Cabinet directed the Ports Authority to let the Pulupaki - which is owned by a Member of Parliament - continue taking on passengers.
The commission heard the penalty for allowing an unseaworthy vessel sail in Tonga is 15 years jail, and a fine of $US130,000 dollars.
Source: Australia Network News
