Mr Singh Gold said on some occasions thieves had gone into shops during the day and looked at staff “dead in the eye” while picking up piles of cashmere and other expensive items.
One staff member has been punched in the face while others have been knocked to the floor.
Some say they receive intimidation and abuse if they try to apprehend thieves.
Mr Singh Gold added: “We have lost several good members of staff because they feel threatened and unsafe at work now.
“We have had staff threatened at work saying ‘I know which bus you catch on the way home and I’m going to be waiting for you’.
“We are sick of calling the police and making reports and downloading CCTV and then nothing happens.”
Calling the problem a “theftdemic” Mr Singh Gold said he was going to have to employ security guards during the day at £8,000 a month.
He said the thieves watched his stores for opportunities to lift whole baskets of products before slipping down nearby closes.
“It’s shocking that it’s allowed to take place on the most prestigious street in the country,” he said.
“The city centre has become lawless and this is where they are getting the brazenness because they know that the systems we have in place with the policing and the control of crime has failed.”
