But the CPS would not comment on suggestions that the report from police - on forensic tests conducted on original evidential material - contained new evidence that would prompt a re- evaluation of the affair.
The re-investigation, known as the Birmingham 74 Inquiry, was ordered after the release by the Court of Appeal in March 1991 of six Irishmen convicted of the IRA bombings in 1975.
The court said their convictions were unreliable because of doubts about police interviews with the men and the evidence of Dr Frank Skuse, the forensic scientist, that there were traces of nitroglycerine on the hands of two of the men.
The West Midlands force has consistently refused to comment on the progress of the new inquiry. Yesterday, Detective Superintendent Brian Wall, who is leading it, would only say: 'I can confirm that we have been carrying out certain inquiries including the forensic re-examination of material from the original investigation. Recent new developments have been notified to the Director of Public Prosecutions, through whom any further comment will be made at this time.' The CPS said yesterday that a final report was not expected for some time.
Scientific testing using techniques not available at the time, and regular progress reports to the CPS, would be routine in such an inquiry.
Scientific advances since the 1970s include the improved detection of fingermarks on fragments from exploded bombs and on surfaces that did not previously appear suitable for fingermarks, the development of DNA fingerprinting on genetic material, and computerised analysis of explosive traces.
Senior West Midlands officers have previously suggested privately that reticence over the inquiry was because any publicity could be prejudicial to the trial of three former detectives charged with perjury and conspiracy in connection with the case.
The three retired officers - George Reade, a former detective superintendent, Colin Morris, a former detective sergeant, and Terence Woodwiss, a former detective constable - are due to stand trial at the Old Bailey next year.
The 20 officers involved in the Birmingham 74 inquiry have interviewed people in Australia and New Zealand. Many of the 162 people who were injured in the explosions at the Mulberry Bush and Tavern in the Town public houses have been re-interviewed.
It is not known whether the detectives have attempted to interview any of the men identified by Chris Mullin, the Labour MP, in his book on the case, Error of Judgement, or subsequently named by Granada Television in the drama documentary Who Bombed Birmingham?
If the Birmingham 74 inquiry provides enough evidence to charge anyone in connection with the bombings, the CPS would decide if it would be in the public interest to pursue a case or whether, if a case was brought, a conviction would be possible.Reuse content