The indictment last week of former Donald Trump campaign aide George Papadopoulos, who admitted lying about contacts with Russia during the 2016 U.S. presidential election campaign, is turning the spotlight on London as an important hub of suspected Kremlin meddling in Western politics, say analysts and Western officials.

Papadopoulos, who White House spokespeople say was a low-level and unimportant foreign policy adviser in last year's campaign, was initially introduced to shadowy Russian contacts by a London-based globe-trotting Maltese academic, according to the indictment of Papadopoulos unsealed last week by special counsel Robert Mueller.

But the British capital is now featuring more prominently than just the venue of meetings between Papadopoulos and Russian officials. Probes launched on both sides of the Atlantic into suspected Russian subversion of last year's White House race and the 2016 Brexit referendum are increasingly highlighting the British capital as a hotbed of Russian intelligence activity that links individuals and groups of interest to investigators in Washington as well as in Britain.

Political pressure is mounting on the ruling Conservative government of Theresa May to launch a broad formal inquiry into whether Moscow sought to influence the Brexit vote.

The demands came as it emerged that three senior past and present Foreign Office ministers, including the current Foreign Secretary Boris Johnson may have been targeted by individuals identified by the FBI last week as central to the Mueller probe.

Mueller is investigating Russia's meddling in the U.S. election and accusations of collusion between Trump campaign aides and the Kremlin. The Trump administration has denied there was any collusion. Papadopolous reached a deal last month with Mueller, agreeing to plead guilty to lying to FBI agents about his contacts with Russian intermediaries during the presidential race.