The Daily Star Sunday says the Hammers are ready to sue Brescia to get money they believe they are owed for Alessandro Diamanti.
The Irons claim they have not been paid money they were due after selling the midfielder for £2m two years ago.
Diamanti – signed from Livorno for £6m in 2009 – was allowed to go home to Italy after just one season, having failed to settle in London.
He then moved on to Bologna earlier this summer following Brescia’s relegation to Serie B.
West Ham are unhappy because they asked for Diamanti’s registration by the Italian Football Federation to be suspended in July last year.
The club acted because they had not been paid a due instalment of their transfer fee by Brescia.