HP bought software group Autonomy in 201, but said this year the UK firm seemed to have "inflated" its value, leading to a five billion dollars write-off.
In a regulatory filing, HP said that the US Department of Justice (DOJ) told it last month that it has opened a probe into the Autonomy deal, the BBC reports.
According to the report, HP said that it was writing off 8.8 billion dollars of the 11.1 billion dollars it paid for Autonomy, of which 5 billion dollars was "linked to serious accounting improprieties, misrepresentation and disclosure failures".
HP had asked US and UK authorities to investigate alleged misrepresentations of Autonomy''s finances before HP took over the company last year, the report added.
The former head of Autonomy, Mike Lynch, has rejected HP''s claims that former Autonomy management misled them as to the company''s value.
He has said he was shocked and appalled by the allegations, the report said.