PSNI detectives investigating the awarding of a number of police vehicle contracts have arrested a 71-year-old man in Co Down.
The suspect is being detained on suspicion of bribery and procuring misconduct in public office.
He is being questioned at the serious crime suite at Antrim Police Station.
Six other men arrested in Northern Ireland and in England on Tuesday as part of the same investigation remain in custody.
Police were granted more time yesterday to question the suspects who include a serving policeman, a former senior officer in the PSNI, a police worker and a civilian.
Two other men were arrested in England and brought to the North for questioning.
A number of searches were also carried out at homes and business premises and items, including computers were seized.