Five men who were accused of plotting to kidnap ex-Spice Girl Victoria Beckham -- the wife of England and Manchester United soccer star David Beckham -- were released and their charges were dropped in London Monday after prosecutors said a key witness's evidence was unreliable, reports Reuters.

"It is no longer possible to say that there is a realistic prospect of conviction," authorities said after a pre-trial hearing at Middlesex Guildhall Crown Court, central London.

The suspects cleared of conspiring to kidnap -- identified as four Romanians and one ethnic Albanian from Kosovo -- included Lulezim Balliu, 30, Adrian Pasaraneu, 27, and Alin Turcu, 18, said Reuters. Two others were cleared of the same charge but cannot be named for legal reasons.

Prosecutors say their main witness, Florim Gashi, 27, had received payment from the tabloid News of the World. Local media reported that Gashi was a parking attendant with money problems who had been paid 10,000 pounds ($16,310) by the paper.

A spokesman for the News of the World said the paper stood by its story and was "perplexed" by the decision to drop the case.

The prosecution had claimed that the five men planned to kidnap the 29-year-old singer last November. The quintet was arrested after details of the alleged plot were published in the News of the World.

The Beckhams, one of Britain's most famous couples (and profiled in the current PEOPLE), reportedly have been surrounded by tight security since an earlier kidnap scare in 2000.