Bill Browder has described himself as "Putin’s No 1 enemy". Now the Russian president had added weight to that claim by singling out the British investor at his controversial summit with Donald Trump on Monday. 

The UK-based financier appeared to be part of what the US president called an "incredible offer" by Vladimir Putin to assist American investigators in their prosecution of 12 Russian intelligence officers accused of hacking crimes during the 2016 presidential election season.

"He offered to have the people working on the case come and work with their investigators with respect to the 12 people," Mr Trump told reporters during a news conference in Helsinki following his joint summit with…