JOHANNESBURG — South African anti-graft investigators have arrested 12 senior police officers on allegations of corruption and fraud, prosecutors said Wednesday.

The officers appeared later in a court in the capital, Pretoria.

The arrests come while an inquiry continues into allegations of high-ranking corruption in the South African police. The inquiry was ordered by South African President Cyril Ramaphosa, who also suspended the police minister last year.

A second inquiry by Parliament is also looking at claims that senior police officers had corrupt relationships with alleged crime bosses and in some cases allegedly received money from them for favors.

The arrest of the 12 officers relates to an allegedly corrupt contract to provide health and wellbeing services to police officers, the National Prosecuting Authority’s anti-corruption investigative unit said in a statement. It said a 13th person, the director of a company, was also arrested.