West Midlands Police has said a "dedicated team of detectives" are working to trace material related to the pub bombings. A statement from the force said:
Considerable progress has been made with over 4,000 individual items collated, which had been previously stored by a number of different locations and organisations. This important work continues.
We have also made a commitment to consult independent forensic experts to assess whether more tests can be carried out.
Officers from the unit have travelled to Europe and engaged with a leading forensic provider.
When we have completed this work we will better understand what opportunities exist to bring to justice those responsible for the pub bombings.