Six men acquitted after one of longest and most expensive fraud trial thrown out by judge.

Two directors of the quantity surveying firm formely known as RWS were last night free men after the two year fraud case against them collapsed.

Stephen Rayment and Mark Woodward Smith, both 44 and directors at RWS, were accused of bribing London Underground executives over contracts and payments to build the £3bn Jubilee Line Extension.

Four others were also freed at the Old Bailey following the failure of the case, thought to have cost £60m and one of the longest fraud trials in legal history. They were: Mark Skinner, 50, a director at Surrey-based QS firm George Skinner & Associates; Anthony Wootton, who was seconded by George Skinner as a claims expert; and two Jubilee Line Extension senior managers Graham Scard, 50, and Paul Fisher.

Judge Ann Goddard cleared the six defendants after the prosecution offered no evidence and said they would not pursue a retrial. Anthony Upward QS said the prosecution's decision to ask for the jury to be discharged was taken with the approval of the Director of Public Prosecutions after a review of the case. The trial, which started in summer 2003, had been kept out of the media by reporting restrictions.

Outside the court Mark Skinner said: "Although I should now feel relief and happiness, I feel only anger. Anger at a prosecution which has destroyed my business and tortured my family. Anger at a prosecution that has caused significant damage to my health. Anger that no one in a position to do so stepped in and ended what to all reasonable observers had become a farce long ago. Anger at the fact that those who have persecuted me to this day - the British Transport Police and the CPS and those instructed by them - fail to accept they got this terribly wrong."

Charges were brought against the six men in March 2000 after a three-year investigation by the British Transport Police, first revealed in Building in 1997. The investigation was believed to have covered the inital award of a number of JLE contracts with a particular focus on contracts 205 and 206, won by M&E specialist Drake & Scull.