Nokia is protesting an investigation into its tax payments in Indian.

Reuters reports that Indian officials are looking into allegations that the Finnish handset maker skipped out on $558 million in taxes.

Gartner estimated that smartphone sales in India could strike as high as 251 million units in 2013. After Samsung, Nokia holds the highest smartphone market share in India, making the country a key marketplace for the company.

The Reuters report adds that British mobile provider Vodafone is similarly under investigation and trying to settle a $2 billion tax dispute.