CONFIDENTIAL documents and sensitive material were removed from waste tips in Warrington and Halton, it emerged on Tuesday.
Bank statements, passports, a pilot's uniform and letters from an MP to a high ranking policeman were among the items recovered from the tips by a concerned a security guard.
Mersey Waste Disposal Authority has said it and site contractor Mersey Waste Holdings will investigate the finds.
The items could be used for identity fraud.
Among the documents found and passed to a regional newspaper were custody records and letters belonging to Cheshire Police.
A Cheshire Police spokesman said: "It is against force policy for this sort of material to be disposed of with the normal waste."
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