Simon Deacon, 47, who was serving a sentence for robbery, was last seen at 1.10pm last Thursday (November 19), police said.
Police said Deacon absconded with a second prisoner, who was subsequently located and arrested by Thames Valley Police on Sunday (November 22).
A spokesperson for Sussex Police said: "He [Deacon] is described as white, 6ft, of stocky or large build and with short brown hair and a fringe.
"Deacon was last seen wearing grey or black Nike jogging bottoms, a cream or light coloured jacket, with a green top underneath and black Nike trainers.
"Deacon has links to West Sussex and Brockley, Greenwich and Sydenham in South East London. He is also known to frequent Northamptonshire, Havant in Hampshire and Harefield in Middlesex."
Anyone who sees Deacon, or knows of his whereabouts, should not approach him but instead call 999 immediately quoting serial 1268 of 19/11.
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