The chair of the US House Intelligence Committee was in London last year asking questions about people who have been investigating Donald Trump. One of his key targets was Christopher Steele, who had written the explosive dossier on Trump and the Kremlin that was given massive publicity.

Devin Nunes was particularly keen on who the former MI6 officer had contacts in the FBI and Justice Department. He asked to meet the head of MI6, Alex Younger, and his counterparts at MI5, Andrew Parker, and GCHQ, Jeremy Fleming. Although it was far from unusual for the chair of the House Intelligence Committee to meet the heads of Britain’s security establishment, all three refused because they were wary, according to officials, of his motives. He had to make do instead with Theresa May’s deputy national security advisor, Madeleine Alessandri.

The visit by Mr Nunes, who was part of Trump’s transition team, was at a particularly difficult time for the president. His personal lawyer and consigliere, Michael Cohen, and former campaign manager, Paul Manafort, were in court.

Mr Nunes had to recuse himself for a while from the investigation after being caught out making secret visits to the White House. The Republican-controlled House Committee published its report in spring last year, with dissenting notes from the Democrat members, and it was seen as whitewash of Trump.

Mr Nunes is no longer the chair of the Intelligence Committee in the Democrat-controlled House, it is Adam Schiff, the former deputy chair who has been a vociferous advocate for investigation. This is a man who can do Trump a great deal of damage, a man he could perhaps have tried to mend fences with. Instead, the president referred to him in a tweet as Adam “Schitt” just after he took the post.

The House Intelligence Committee, under Schiff, said today that it has requested Robert Mueller to testify – and it has reopened its investigation into Mr Trump. The Mueller report reveals one reason why the special counsel did not conclude whether Mr Trump was guilty of obstruction – Justice Department policy that a sitting president could not be prosecuted for a crime. This, a number of analysts has pointed out, leaves it to congress to make the constitutional decision whether Mr Trump can be charged.

Mueller investigation: The key figures Show all 12 1 /12 Mueller investigation: The key figures Mueller investigation: The key figures Robert Mueller is the special counsel overseeing the investigation into Russia's meddling in the 2016 election, and potential obstruction of justice by the president. Mr Mueller has a pristine reputation in Washington, where he was previously in charge of the FBI. Throughout his investigation, he and his team have been notoriously tight lipped about what they know and where their investigation has led. REUTERS Mueller investigation: The key figures Former FBI director James Comey was the catalyst that led to the appointment of special counsel Robert Mueller. Mr Comey was fired by the president after Mr Trump reportedly asked him to drop his own Russia investigation. Mr Trump has long maintained that the investigation is a "witch hunt". AFP/Getty Images Mueller investigation: The key figures Deputy attorney general Rod Rosenstein had authority over the special counsel investigation for much of the two years it has been active. Mr Rosenstein found himself with that responsibility after then-attorney general Jeff Sessions recused himself from that oversight. AP Mueller investigation: The key figures Attorney general Jeff Sessions's decision to recuse himself from oversight of the special counsel investigation may have cost him his job in the end. Mr Sessions resigned last year, after weathering a contentious relationship with Donald Trump who vocally criticised his attorney general for taking a step back. Mr Sessions recused himself from the oversight citing longstanding Justice Department rules to not be involved in investigations overseeing campaigns that officials were apart of. AP Mueller investigation: The key figures Attorney General William Barr is currently responsible for oversight of the special counsel investigation. Mr Barr's office will be the first to receive the Mueller report when it is finished. His office will then determine what portion or version of that report should be delivered to Congress, and also made public. EPA Mueller investigation: The key figures Michal Cohn is the president's former personal lawyer, who has been helping the special counsel investigation as a part of a plea deal over financial crimes, and campaign finance crimes, he has pleaded guilty to. Among those crimes, Cohen admitted to facilitating $130,000 in hush money payments to adult film actress Stormy Daniels during the 2016 campaign. Cohen has said he did so at the direction of Mr Trump. Cohen has also admitted that he maintained contacts with Russian officials about a potential Trump real estate project in Moscow for months longer than Mr Trump and others admitted. The talks continued well into 2016 during the campaign, he has said. AP Mueller investigation: The key figures Stormy Daniels has alleged that she had an affair with Donald Trump in 2006, soon after Melania Trump gave birth to Baron Trump. The accusation is of particular importance as a result of the $130,000 hush money payment she received to keep quiet about the affair during the 2016 campaign. AP Mueller investigation: The key figures Paul Manafort was Donald Trump's former campaign chairman. Manafort was charged alongside Rick Gates for a slew of financial crimes, and was convicted on several counts in a Virginia court. He then pleaded guilty to separate charges filed in a Washington court. Manafort has been sentenced to just 7.5 years in prison for his crimes — in spite of recommendations from the special counsel's office for a much harsher sentence. AP Mueller investigation: The key figures George Papadopoulos was one of the first individuals associated with the Trump campaign to be charged by the Mueller probe. He ultimately received a 14 day prison sentence for lying to investigators about contacts he had with Russian officials. AP Mueller investigation: The key figures Roger Stone is a well known political fixer and operative, who has made a name for himself for some dirty tactics. He has been charged by the Mueller probe earlier this year, and he has been said to have had prior knowledge that WikiLeaks planned on publishing stolen emails from the Hillary Clinton campaign in 2016. Getty Images Mueller investigation: The key figures Rick Gates was charged alongside former Trump campaign chairman Paul Manafort for a range of crimes. Gates, who worked alongside Manafort for a pro-Russia Ukrainian political party. The two were charged with conspiracy and financial crimes. Gates pleaded guilty. AP Mueller investigation: The key figures Former national security adviser Michael Flynn was one of the first casualties of the Russia scandal, and was forced out of his position in the White House weeks after Donald Trump took office. Flynn pleaded guilty in 2017 to "willfully" making fraudulent statements about contacts he had with Russian officials including former Russian ambassador to the US Sergey Kislyak. Flynn then lied to Vice President Mike Pence about that contact. REUTERS

This House inquiry is possibly the most hawkish in keeping after Mr Trump, but there are about 20 different continuing probes into Mr Trump, his family and associates, by congressional committees and federal and state prosecutors. And no fewer than 14 of these inquiries have received information gathered by the special counsel’s team and passed it on because it did not fit in with the focus of their task.

Just 48 hours before attorney general William Barr gave his press conference claiming that Trump had been cleared, a performance for which he was criticised for acting like the president’s defence attorney, House Democrats were issuing subpoenas for information from Deutsche Bank and other financial institutions in their investigation of Mr Trump.

As we know from redacted copies of the Mueller report, when told of the appointment of a special counsel, the president “slumped back in his chair and said, ‘Oh my God. This is terrible. This is the end of my presidency, I’m f****d’.”

The 675-day inquiry may be over, but Trump and his supporters have long complained that Mueller was going beyond his remit. Now the president’s critics know that what he gathered has not been wasted but taken up by other investigators.

The special counsel, we have seen, pointed to “10 episodes” in which Mr Trump engaged in potential obstruction of justice. Barr insisted that there was no evidence to bring charges and reiterated that there was no collusion between Russians and the Trump team.

But the Mueller report also states that Mr Trump ordered a number of his team, former attorney general Jeff Sessions, lawyer Don McGahn, and former campaign manager Corey Lewandowski, to sabotage the Russia inquiry – but they refused.

The ongoing investigations are looking for evidence of both collusion and obstruction. The Democrats who have launched investigations maintain that just because the president failed in his attempts to obstruct justice, he is not absolved from possible charges of conspiracy to obstruct.

The House Intelligence Committee has expanded its scope by looking in particular at Russian organised crime. This is in response to claims that Russian loans received by Mr Trump were in fact illicit funds being laundered.

Other lines of inquiry being pursued by the committee include the extent of contact between the Trump team and Russia, influence on Mr Trump and his coterie from other foreign states, and whether Trump obstructed justice.

One of the key events which emerged during the Mueller investigation was a meeting at Trump Tower in New York, between Donald Trump Jr, Trump's son-in-law Jared Kushner, his then campaign manager Paul Manafort, and a group of Russians, some of them with links to the country’s security apparatus. The meeting was allegedly arranged so a Russian lawyer could pass on dirt on the Clinton campaign.

Michael Cohen claims that Donald Trump knew about the meeting despite his denials that was the case. The Mueller report states that Trump directed aides on multiple occasions not to disclose emails setting up the meeting, and Trump himself dictated a misleading statement. But the special counsel concluded that president’s actions were not criminal acts. The report also states that it did not prosecute Donald Jr and others because it could not be proved that they had “wilfully” violated the law.

The damage to Hillary Clinton’s campaign through the hacking of her and Democrat party emails is another avenue the House Committee is said to be taking. The information was stolen, according to Mueller indictments, by Russian military intelligence officers, some of whom were in touch with WikiLeaks which then made it public. The committee is said to be looking at allegations against WikiLeaks and its founder Julian Assange, who is now in police custody in London after being arrested at the Ecuadorian embassy where he had been granted asylum for seven years.

Continuing investigations into Trump are examining what took place from the very start of his presidency. The US Attorney’s Office for the Southern District of New York is examining the finances of Trump’s inauguration committee, which took in and spent $107m (£80m). The FBI raised concerns about some of the Russians who appeared at the inauguration and other eastern European connections. Sam Patten, an associate of Mr Manafort, has admitted that he helped a Ukrainian businessman put $50,000 into the inauguration.

Prosecutors subpoenaed a range of documents from the committee with apparent particular interest in money donated with connection to the UAE, Saudi Arabia and Israel – states that have financial ties with Trump or his son-in-law Jared Kushner. They are also believed to be looking at claims that China and Qatar also targeted Kushner, who is a White House senior advisor.

Mr Mueller passed on information to New York attorneys about Mr Manafort. They are now looking at whether Mr Manafort, when chair of the Trump campaign, illegally coordinated with a super PAC, Rebuilding America Now, and whether the PAC received money from Qatar and other Middle Eastern countries. Michael Cohen has testified to congress that prosecutors are examining his communications with Trump and Trump’s representatives following FBI raids on his offices in April 2018.

New York investigators are looking at Trump’s finances after The New York Times reported that he had benefited from more than $400m in various tax schemes. And the New York attorney general has charged the Trump Foundation with “violations of campaign finance laws, self-dealing and illegal coordination with the presidential campaign”. The attorney general has said, the go-ahead from a judge, that he is expanding his inquiries into Trump’s broader business activities.

Meanwhile, the attorney generals for Maryland and District of Columbia have sent subpoenas to the Trump Organisation – a real-estate company – over the Emoluments Clause of the US Constitution. This clause bars the president from accepting payments from foreign governments while in office. The case is expected to yield evidence that various countries have done deals with Trump’s business – for example, the Saudi government booked more than 500 rooms in Trump’s hotel in Washington in the months after the election.