The UK has exported £5 billion ($6.8 billion) worth of weapons to oppressive regimes around the world since the Conservatives came to power 22 months ago, the Guardian newspaper reported.
Arms sales to Saudi Arabia have been pinpointed as the main cause of the increase. In 2015, the Kingdom setup an Arab coalition to battle in Yemen. Since then it has faced criticism that it has repeatedly and indiscriminately attacked civilians in violation of international humanitarian laws.
In July, campaigners brought a case to the British High Courts in the hope of forcing the UK government to stop selling arms to Saudi Arabia, weapons they say were being used in its war on Yemen. However the court ruled that the UK can continue to sell arms to Saudi Arabia.
The news comes as the UK hosted the Defence and Security Equipment International exhibition (DSEI), which advertises itself as "the world leading" arms industry fair.