CASH was stolen from Ladbrookes in Goring on Saturday (October 12) after a member of staff was threatened with a knife.
A white man wearing dark clothing entered the Limbrick Lane shop at 6.55pm.
No one was injured and the man ran off with a quantity of cash.
A 26-year-old man from Littlehampton was arrested on Sunday 13 October on suspicion of robbery and remains in custody for questioning.
Detective Sergeant Chris Leech said: “Police are appealing for witnesses who may have seen anyone acting suspiciously near to the betting shop or who witnessed the incident. If anyone saw a vehicle close by then we will also be interested in hearing from you.”
Anyone with information should call 101 quoting serial 1309 of 12/9 or email firstname.lastname@example.org