The 67-year-old Costa Panayiotou just closed his shop in Market Street and was walking towards his vehicle with his assistant when unknown men accosted him near the Town Hall parking space where he was fatally shot.
Spokesperson Sergeant Majola Nkohli says Panayiotou was shot in the upper body.
He says it is also said that the suspects abducted Panayiotou's assistant who was later found in Kwazekhele.
Nkohli says she immediately went to the nearest police station where she reported that she had been raped by two suspects.
Nkohli says they also stole his Volkswagen Polo which was found abandoned in front of a house in NU-9 in Motherwell, Port Elizabeth.
He says a charge of rape is also now under investigation.
Any person with information that can lead to the arrest of the suspects is urged to contact the investigating officer, Detective Captain Josh Victor at 082 319 9204 or 041 922 0723.
Callers can remain anonymous.
Costa Panayiotou is the father of convicted killer Christopher Panayiotou who is serving out a life sentence in prison for planning a hit on his wife Jayde.