Critics said it was a preferential treatment given to the former president considering that she was, after all, an arrested criminal suspect under investigation.

The detention house, however, said it was an "inevitable" decision to avoid Park's contact with other inmates, citing security reasons.

The repair works reportedly included replacing wallpaper in Park's cell.

There have been suspicions that a cell refurbishment was requested by the former president, but the detention house denied them, insisting that the wallpaper had not been replaced since 2013.

Park was formally arrested late last month over a string of allegations including bribery, abuse of power, coercion and leaking government secrets. Prosecutors are expected to level formal charges against her next week. (Yonhap)