The Magpies have appeared to be closing on a deal for the Brazilian full-back on several occasions in the recent past, only to miss out on his services for various reasons.
It was expected that a switch would finally be pushed through this summer, with Douglas having dropped into the free agent pool after seeing out his contract at Twente.
Newcastle have, however, ended their interest in the wake of Joe Kinnear's arrival at St James' Park as director of football.
They are now exploring other options, leaving Douglas free to talk with other clubs.
Hannover are willing to offer him a fresh start in Germany, with defensive reinforcements required on the back of a failed attempt to extend Johan Djourou's loan from Arsenal.
"We are looking to sign a defender and we are interested in Douglas," Hannover chairman Martin Kind told BILD.
"Signing him would be very good business for our club."