Eighteen priests including 15 Buddhist monks are currently in prison, an organization called the Sri Lanka Human Rights Centre said.
Of them 15 priests are Buddhist monks who have been convicted by court of law.
A Hindu priest currently serving a prison sentence has been convicted for conspiring to murder former President Chandrika Bandaranaike Kumaratunga.
The organization said all of them have accepted rules and traditions of the Prisons Department and have not raised concerns over wearing the dress worn by prisoners.
This comes in the wake of the conviction against Bodu Bala Sena General Secretary Galagoda Aththe Gnanasara Thera.