41-year-old George Melseaux pleaded guilty to laundering money from victims using fake online identities.
Five members of the group have been sentenced including Kwabena Edusei from East Finchley and Fawaz Ali from London.
Surrey and Sussex Police say the network defrauded at least 99 victims worldwide, causing serious financial and emotional harm.
Detectives urge anyone who think they may have been a victim of romance fraud to report it.
