Tonga's chief secretary and secretary to cabinet, Busby Kautoke, has been suspended from his post by the Public Service Commission.
The deputy secretary of the Prime Minister's office, Alfred Soakai, is now acting in Mr Kautoke's role.
Mr Soakai says the suspension was made effective last Thursday but no reason was given.
He says, however, the commission will lay charges against Mr Kautoke in relation to the public service code of conduct, but that they are not criminal charges.
He says the probe of Mr Kautoke's action is likely to take between one to two months.