It said: "Development of Prey 2 has not been cancelled but the game will not be released in 2012 as planned. The delay is due to the fact that game development has not progressed satisfactorily this past year, and the game does not currently meet our quality standards.
"Prey 2 has shown great promise and we regret disappointing our fans. We have made a substantial investment in game development to deliver the experience fans want. We are determined only to release the AAA game that fans rightfully expect, and are unwilling to compromise our quality standards to meet a release schedule."
Unlike the linear shooter gameplay offered by 2006's well-received original, Human Head has said Prey 2 will feature an open world for players to bounty-hunt aliens in.
Last month Brian Karis, lead graphics programmer at the developer, said he'd been left "pretty devastated" after Bethesda parent company ZeniMax Media forced the studio to pull a series of planned Prey 2 talks at GDC.