Sources close to the inquiry into the roof fall that killed three men at the Nottinghamshire colliery said initial impressions of union officials about the nearness of old workings to the site of the disaster were wrong.
Unions reported that there was a metre of coal separating the new roadway from the old, which they regarded as insufficient. However, sources now say that at least one point there was nothing between the tunnels. It was possible to walk from one to the other. Brian Langdon, deputy chief inspector of mines, who is leading the initial investigation into the accident, has already indicated that the old workings might have been the main cause of the accident.
Peter McNestry, general secretary of the pit supervisors' union Nacods, said that if there was nothing to separate the roadways, colliery inspectors should have refused to sanction the operation. He said the new evidence meant that the roof bolt system used was inappropriate.
Roof bolts, used for many years in the American industry, have been introduced into Britain. Mr McNestry's union and the National Union of Mineworkers have opposed this, although the Union of Democratic Mineworkers, the main union at Bilsthorpe, has been less hostile.
Both the NUM and Nacods are worried that there could be a 'cover-up' of the true causes of the disaster. They believe that unsafe practices are increasingly being used to improve productivity ahead of privatisation and to avoid pit closures. The future of Bilsthorpe itself is uncertain.
Visiting the colliery yesterday, the energy minister Tim Eggar said any lessons learned from the tragedy would be applied to other collieries.
Labour MPs and some union leaders have criticised plans to reform pit safety regulations and Nacods yesterday decided to seek a judicial review. The new regime would do away with Nacods members' right to stop work they think potentially dangerous.
Mr Eggar said the new regulations followed many years of consultations and there had been an elaborate period of re-examination. It was the view of the Health and Safety Commission that the new regulations would improve safety standards, he said.
Mick Stevens, UDM secretary for Nottinghamshire, told Mr Eggar that the three men would have died in vain if Bilsthorpe closed.