FASHION has always been a rapacious business. Labels are counterfeited; designers plagiarise each other's ideas; high street stores plunder the catwalk shows for next season's styles. Now this trend has been taken to its logical conclusion, with the literal theft of entire collections.

In the past week, three London-based designers have fallen victim. On Monday, Effi Zamara, whose clients include socialites Tamara Beckwith and Liz Brewer, arrived at the store she opened off New Bond Street just a fortnight ago to find that all of her stock - 250 suits, dresses and knitwear pieces - had been stolen.

The following day, it was the turn of Antonio Berardi, British Designer of the Year, whose autumn/winter designs were the highlight of London Fashion Week in February. The collection, worth up to pounds 500,000, was snatched from outside his London studio, where it was being unloaded.

On Thursday, the swimwear designer Lisa Bruce arrived at her Knightsbridge shop to find that burglars had smashed through her glass door and taken her entire 1998 stock, worth pounds 100,000. The shop had been open for just six weeks. It marked the relaunch of Ms Bruce's career, after she was forced to liquidate her company two years ago as a result of a legal battle with Marks & Spencer, whom she accused of copying her designs.

It will come as little consolation to Ms Bruce, as she contemplates her ranks of empty rails, to learn that she is in illustrious company. Some of the biggest names in the fashion world have suffered similar raids in recent years, including Christian Lacroix, Bruce Oldfield, Issey Miyake, Mulberry, Hermes and Liz Claiborne.

Scotland Yard detectives are investigating possible links between the three latest incidents. They say it is too early to say whether they were ordinary burglaries, or whether the designers were targeted by professional thieves. Ms Bruce said yesterday: "Someone is trying to put me out of business. I have to ask myself who my enemies are."

Priyesh Shah, Mr Berardi's business partner, is convinced that the theft of their designs was not opportunistic, pointing out that it seems to have been carefully planned and executed. When the van drew up outside the studio, the driver was approached by two men pushing trolleys who asked him whether it was the Berardi delivery. He assented, and the men wheeled away the 180 pieces, leaving the driver nonplussed. "It may have been people just taking pot luck," said Mr Shah. "But it seems far more likely that the collection was stolen by someone who wanted to copy Antonio's designs, or by a rival designer who wanted to sabotage his work. It does happen."

Police believe that few of the samples taken by professional thieves end up on market stalls with the labels cut out - they are too instantly recognisable and tend to be in tiny sizes, made for skinny models. It is far more likely, they say, that the designs are sent to counterfeiting factories in south-east Asia where they are copied with tiny variations and mass-produced.

Mr Shah believes that some garments are stolen to order on the whim of wealthy women. "It used to be for clients in the Middle East, now it's mainly Russia," he said. "The irony is that organised fashion crime is commonplace in Italy, where Antonio comes from. He never expected anything like this to happen in London."