Saudi authorities have arrested dozens of high ranking officials including the billionaire prince who owns the Savoy Hotel in London in an anti-corruption crackdown that strengthens Crown Prince Mohammed bin Salman's grip on power.

Police arrested 49 people including 11 princes, four ministers and tens of former ministers in raids across Riyadh, the Saudi capital, in the early hours of Sunday morning.

Royal planes were grounded as authorities swooped in, corralling princes, former officials and media tycoons into five-star hotels across the capital for questioning.

The arrests include relatives of Mohammad bin Salman, 32, and came just hours after the launch of a new anti-corruption mechanism he oversees.

The detainees include Prince Alaweed bin Talal, a multi-billionaire who has major stakes in News Corp, Citigroup and Twitter. He co-owns the Four Seasons hotel chain along with Microsoft’s Bill Gates, and he is sole owner of London's landmark luxury hotel, the Savoy.