A British police watchdog said Thursday it had identified 13 retired or serving police officers as "suspects" during an ongoing investigation into the 1989 Hillsborough Stadium disaster.
The Independent Police Complaints Commission (IPCC) said 11 of these had already been interviewed relating to a range of offences including manslaughter as well as perverting the course of justice.
A spokesman said the other two would be interviewed in the near future.
In total, 96 Liverpool fans lost their lives when, standing on a terrace at the Hillsborough ground in Sheffield, northern England, they were crushed to death during an FA Cup semi-final against Nottingham Forest on April 15, 1989.
The tragedy, Britain's worst sporting disaster, saw the match abandoned six minutes after kick-off.
Fresh inquests into the deaths are due to begin in Warrington, near Manchester, on Monday after the High Court in London quashed the original coroner's verdicts following a campaign led by relatives of those who died.
The IPCC investigation -- the largest it has undertaken -- into police handling of the disaster is underway as well, after evidence emerged the local South Yorkshire Police force tried to cover up what had happened on the day of the tragedy.
The watchdog, which hasn't named any of the 13 "suspects", said it could not give any further information or figures for how many had been questioned regarding allegations of manslaughter.
The coroner was told Thursday the BBC had found an hour of unseen footage of the disaster which is now being considered by lawyers.
Pete Weatherby, an advocate representing 21 families, said: "There is at least an hour of it. It is within the stadium at relevant times."
He added the BBC had previously said it had handed over everything it had but that this footage had been found recently.
No further details of the footage were given in court on Thursday.
Under English law, the purpose of an inquest is to determine the course of events that led to a death.
Next month, on the 25th anniversary of the disaster, matches in England will kick off seven minutes late as a mark of respect.
The matches affected include the FA Cup semi-finals at Wembley Stadium between Arsenal and Wigan Athletic and Hull City and Sheffield United, as well as Liverpool's league game at home to Manchester City. All the games will also be preceded by a minute's silence.