The recent spate of shopping mall robberies could be the result of security companies being penetrated by criminal syndicates, a crime researcher has suggested.

Last week a jewellery store at Canal Walk was the third store in as many months to be robbed at the centre. Men broke a glass display case with a crowbar and fled with goods valued at R500 000. Other malls around the city and the country have also been hit and staff injured.

Jackson Madzima, a researcher at the Institute for Security Studies' organised crime and money laundering division, said the fact that the robberies are taking place is "testimony that the security systems are not as effective as they should be to stop criminals".

Madzima said: "The incidence of robberies suggests it is relatively easy for criminals to access shopping malls. Either the technology is ineffective or the personnel using it are not competent enough. Otherwise we could assume they have been penetrated by criminal syndicates and are probably facilitating the robberies".

Most shopping centres in the Western Cape have CCTV cameras and security guards, but no measures to stop people carrying weapons. Madzima said he was not aware of any shopping malls with metal detectors at the entrances.

"Theoretically, metal detectors could be installed. However, there are associated shortcomings that mall owners might consider prohibitive," he said, citing a halt to the free flow of customers in and out of malls.

Vanessa Herbst, spokeswoman for Canal Walk, said they were not taking the robberies lightly, and would continue to adjust security to a level that would ensure the safety of shoppers and tenants.

She said although their security guards reacted "swiftly" on Monday there had been no arrests.

"Each shop has a panic button that can alert security and ensure that any situation is attended to in minutes. The security guard noticed the suspects running to the exit and immediately alerted security control.

"According to our CCTV footage, within one minute a further three security staff had responded to the alert and attempted to follow the suspects. Century City security was also immediately alerted and the armed response vehicle responded to the search for the suspects."

Earlier this year there was a robbery at the Checkers store and an attempted robbery at John Dory's steakhouse.

"We have extensive security measures, including closed-circuit television, 24-hour patrols by uniformed guards, an armed response vehicle and undercover plain-clothes guards," Herbst said.

Police spokesman, Superintendent Andre Traut said the incidence was "a cause of concern".

"Although our analysis indicates no significant increase in this trend, it is concerning that criminals are becoming more brazen and reckless by operating in retail areas filled with people."

Shopping centres in one of the sectors of a police station's precinct now have the benefit of sector policing, where dedicated human resources and vehicles are assigned to the area for operational purposes, Traut said.

Monday night's robbery at the ITA Jewellery store at Canal Walk around 8pm was just the latest in a succession of similar incidents.

• Last month a jeweller in Somerset Mall was shot by armed robbers and Harris Jewellery at the V&A Waterfront was hit by an armed robber who stole jewellery worth R10 million.

• In May, a group of armed men posing as customers stormed the Ackermans store in Vangate Mall and left with R2 000. The same month saw the attempted robbery at John Dory's at Canal Walk, in which an employee was shot in the neck, and three armed men got away with R30 000 from the Fairbridge Mall in Brakenfell.

• In April armed men robbed an Easter egg stand in Canal Walk and a store manager was shot in the foot.

• In Durban a jewellery store was hit earlier this week when robbers posing as customers entered Natal Wholesale Jewellers in Westwood Mall and stole jewellery and cash.

• In addition to the robberies, 38 vehicles were stolen from shopping centres in greater Cape Town between April 15 and May 29.

Community Safety MEC Lennit Max said earlier that mall attacks could not be prevented by increased policing as this would not be conducive to a shopper-friendly environment.

The Shopping Centre Security Initiative, a partnership between the SA Council of Shopping Centres, SA Property Owners' Association and the Consumer Goods Council of SA Business Against Crime, has been meeting police and the Department of Community Safety about improving safety measures.