Immigration officers swooped on a Stanmore cash and carry ware-house in search of illegal workers - only to find they all had the correct documentation.
A total of 17 officers from the UK Border Agency and three police officers descended on Makbros Limited, in Dalston Gardens, just after 10am yesterday.
The raid, codenamed operation Gorcyra, was following a tip-off that the company was employing illegal immigrants.
However, after detaining and questioning five men, officers discovered they all had the documentation to work in the UK, although the employers of the company did not have the documents for the men on site. Immigration officers issued the directors with a notice of potential liability, which could lead to a fine of up to £10,000 per worker.
Mark Allen, officer in charge of the operation, said: "The employers were very co-operative and we have issued a notice for two offences.
"The employers say they have the records but not on site. We have to decide what fine to send to them."
Nearby residents were shocked to see officers rushing into the premises. A worker at a wholesalers in Dalston Gardens, who did not wish to be identified, said: "It was quite scary with all these people running up, driving in and raiding the place like that.
"I've never seen anything like it." A director of Makbros said: "We are happy that everything was OK and they did not find any illegal immigrants, and we understand they have to do their job.
"We are confident we have the information they need and it is unlikely we will have a heavy fine.
"We are doing everything by the book, but for a small business if you slip up on one thing people will come down on you."