Greg Disbrey, 27, was convicted of burglary and handling stolen goods in London in August 2012 and was serving a three-and-a-half-year sentence. He is now unlawfully at large.
He is described as white, 5ft 7in, of medium build, with cropped light brown hair and blue eyes.
He has a pierced left eyebrow, two large moles behind his right ear and a tattoo of a cross on his right forearm. He speaks with a London accent.
He has links to Edgeware in north London and Devon.
Disbrey’s disappearance follows that of Lucas Lamb who walked out of Ford prison on Friday (September 5).
Lamb, 31, was convicted of GBH with intent in Hailsham in October 2012.
He is described as white, 5ft 8ins, thin with short brown hair and blue eyes with a tattoo on his lower neck which says Cleo and has a scar above his right eye. He has links to Hailsham and Eastbourne areas.
Anyone with information about where either of the prisoners are or who have seen them, are asked to contact police immediately on 999 and not to approach them.