The inquiry led English police to detain Mandaric and Redknapp, tipped as a candidate to replace Steve McClaren as England national team coach, Portsmouth chief executive Peter Storrie, Scottish agent Willie McKay and Senegalese midfielder Amdy Faye, currently on loan from Charlton to Scottish club Rangers.
On his release by police, Redknapp was quoted by the BBC as saying: "We all helped the police with their inquiries but it doesn't directly concern me, it's other people involved. I've been answering questions to help the police. I am not directly concerned with their inquiries. They have to arrest you to talk to you, for you to be in the police station. I think that's the end of it, it didn't directly concern me."
The Serbian-born Mandaric, who made his fortune in the early days of Silicon Valley, owned outdoor and indoor teams in the NASL, MISL and CISL and teams in Europe. Mandaric, who previously owned Portsmouth, said via a spokesman that he had assisted London police with their inquiry into a matter that went back to 2003.
A London police spokesperson told Reuters: "They have been arrested on suspicion of conspiracy to defraud and false accounting. It's part of an ongoing investigation into football corruption."