The Independent Police Complaints Commission has asked all police forces in England and Wales to conduct searches of their archives to identify and provide any documentation they have relating to events at the Orgreave Coking Plant in 1984.
South Yorkshire Police has already referred itself to the Police Complaints Commission over its involvement in the "Battle of Orgreave".
But they say any inquiry would take some time because of how long ago the events took place.
Fighting broke out between miners and police at Orgreave Colliery during the miners' strike in 1984.
A campaign group which is demanding a public inquiry into how police dealt with miners in Orgreave meets tonight.
The 'Orgreave Truth and Justice Campaign' will meet in Rotherham tonight.
The group has accused South Yorkshire Police of falsifying witness statements relating to the so-called Battle of Orgreave during the miners' strike.
The group was set up in December and members claim police falsified official accounts about what happened on the day - when fighting broke out between miners and police at Orgreave Colliery during the miners strike in 1984.