According to The Sun, the theft was carried out by a man resembling Albert Square hard man Phil Mitchell.
Richie, who plays Walford's Alfie Moon, has now installed a police e-fit - an image of the man based on eyewitness accounts - on his dressing room door.
The newspaper also claims that the man has been spotted trespassing in the dressing rooms of Holby City cast members.
An insider claimed: "He hasn't forced any doors so it does seem like he has a pass.
"He just strolled into Shane Ritchie's dressing room and stole his iPad and cash. Cars are being searched on the way out and everybody is getting interviewed about it.
"The e-fit is everywhere. He is balding and white and looks a bit like Phil Mitchell."
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