The US Justice Department and the Securities and Exchange Commission started wondering how Vole flogged its software such as Word and Excel to middleman firms in Hungary at such steep discounts.

The intermediaries then sold that software to Polish government agencies during 2013 and 2014 at close to full price, the report said.

Investigators became concerned that the middleman companies used the difference to pay bribes and kickbacks to government officials.

Microsoft insiders find it difficult to accept that Vole would be in the game of paying bribes. This is because every year it whips its voles into the staff training burrow to carry out yearly anti-corruption and good business practices training.  It is emphased that bribery is a really big no-no.

So far Microsoft has yet to comment on the accusation.