“We have 300 boxes of material, some of which has been seen and some of which has not.”

Mr Hughes denied there had been a cover-up by his force and said he would not have stood for it if there had been.

He added: “If I thought there had been a cover-up, I would already have dealt with it. I don’t need an anniversary to make me want to put right an injustice.

“I didn’t join the police force to be part of conspiracies and cover-ups and I never have done.”

Asked if he thought there should be new inquests into the 96 deaths, he said: “That really is not for me to say. But I would be highly surprised if there’s anything in these files after 20 years that causes such a major reappraisal of the disaster that was Hillsborough.”

Ninety-six Liverpool supporters died in a crush at Sheffield Wednesday’s Hillsborough stadium on April 15 1989 where their team was to meet Nottingham Forest in an FA Cup semi final.

The victims’ families have been fighting for further inquiries into the deaths.

They believe a Major Incident Plan was never initiated by South Yorkshire Police and fans at the Leppings Lane end were denied emergency medical attention.

The families also dispute the findings of the single inquest into all 96 deaths, which ruled the victims were all dead, or brain dead, by 3.15pm and which subsequently recorded a verdict of accidental death.

Earlier yesterday, Culture Secretary Andy Burnham today paid tribute to the “dignity” of the families of the victims of Hillsborough as he welcomed moves to release official documents relating to the tragedy.

Mr Burnham’s appearance at the memorial service last week was marked by heckling from sections of the crowd at Liverpool’s Anfield stadium angry that no one has been held to account for the deaths.

In response to a question from Labour former minister Derek Twigg, the culture secretary told MPs: “These events are still unbearably painful and very difficult to talk about, particularly in a public context.”

He added: “I believe that it is not right to expect the families who have suffered so much in the 20 years since the disaster happened . . . to wait a further 10 years to receive full disclosure of the documents.

“I favour very much the full disclosure of all documents held by any relevant public body that was connected with the tragedy.”

Mr Burnham was attending the other semi-final on the day of the disaster, watching Liverpool’s local rivals Everton, and said he would “never ever forget” how he felt when news came through.

Later, Mr Twigg asked the Speaker to investigate why documents were not released 11 years ago.

FOR more stories on Hillsborough, see our dedicated online Hillsborough section at liverpooldailypost.co.uk/ hillsborough