Saudi billionaire Prince Alwaleed bin Talal and his investment firm now own more than 5% of Twitter, his office has said.

Kingdom Holding has paid $50m (£33m) to double its stake in the microblogging site to 0.72%, the Riyadh-based company said in a separate bourse statement on Wednesday.

The prince personally has a 4.45% stake in Twitter, according to Reuters’ calculations. The statement from his office did not say whether that had changed.

The Saudi billionaire and Kingdom Holding first invested $300m in Twitter in 2011. Prince Alwaleed owns 95% of Kingdom Holding.

Twitter listed on the New York stock exchange in November 2013. Its market capitalisation is $18.7bn, according to Reuters data.