LONDON (AFP) – US social media giant Facebook’s British tax bill tripled to £15.8 million ($21 million, 18 million euros) last year, according to a company filing.

The bill compared with £5.1 million in 2016, Facebook’s British division revealed in an official document lodged last week.

Media reported however that Facebook UK’s net tax bill for 2017 will stand at £7.4 million, due to a tax relief credit of more than £8.4 million on employee stock awards.

Facebook UK’s revenues meanwhile swelled by 50 per cent to £1.26 billion last year compared with 2016.

But pre-tax profits increased by just seven per cent to £62.7 million.

The news comes amid political and public unease over the levels of taxes paid by hi-tech giants like Amazon, Apple, Facebook and Google.

Recent media reports suggest that British finance minister Philip Hammond will launch a new digital services tax to stop some US groups funnelling sales income through other countries to cut their tax bills.

The measure is reportedly due in Hammond’s budget statement which is due on October 29.