Updated

Police say a brother and sister were held prisoners against their will by relatives for over seven months near the northern Greek city of Thessaloniki and forced, under threats of violence, to transfer large amounts to their captors' bank accounts.

Police say a 58-year-old man, his 23-year-old daughter and an unnamed accomplice were arrested Friday night over the abduction of a man, 47, and a woman, 48, the older suspect's cousins, on July 27 in the city of Serres, east of Thessaloniki.

The two, whom police officers describe as "cognitively impaired," were forcibly held at the man's house and were restrained with handcuffs and flexicuffs most of the time.

The brother and sister were forced to transfer 81,000 euros ($100,000) to their captors' accounts.