Could imperial gold production support Britain's monetary policy?

How much of world gold production did the British Empire control?

A large share, with no percentage given, but insufficient in this assessment to let Britain dictate the gold market.

The British Empire is said to control a substantial share of gold production, with South Africa among the examples. No percentage is supplied. The answer argues that this still gave Britain insufficient control to dictate the market and points to strains in the gold standard before 1914.