Three people have been placed under arrest warrants in the corruption investigation at Haren prison, the Brussels Public Prosecutor's Office announced on Thursday.
They are a 27-year-old woman and two men, aged 26 and 39.
The three are suspected of selling and possessing narcotics, selling and possessing narcotics in association, being a member of a criminal organisation, and public corruption.
A fourth person, a 33-year-old woman, was suspected of unlawful possession of narcotics and was released unconditionally.
