The former banker claims Vladimir Putin runs Russia like a crime syndicate. He should know: corrupt officials seized his assets and stole $230m. His lawyer was beaten to death in jail. And now sinister text messages warn he might be next

I’m due to meet Bill Browder at Mari Vanna, a favourite hangout for rich Russians in Knightsbridge. But when we get there the restaurant, with its rustic dacha-style Russian decor, leaves us both feeling slightly spooked. So we wander across the road to an anonymous sushi bar. Browder’s reluctance to avoid bumping into anyone with Kremlin connections is understandable. As he explains, matter-of-factly: “They [the Kremlin] threatened to kill me. It’s pretty straightforward.”

American-born Browder is one of Vladimir Putin’s most prominent critics. For over a decade he lived in Moscow and ran the most successful investment fund in Russia. Initially, he was a fan of Putin’s. But in 2005 he was deported from the country. A corrupt group of officials expropriated his fund, Hermitage Capital, and used it to make a fraudulent tax claim. They stole $230m (£153m).

Stuck in London, Browder hired a team to fight his case. The same Russian officials arrested his lawyer, Sergei Magnitsky, after Magnitsky uncovered the money trail and made a complaint. They put Magnitsky in jail and refused him medical treatment. (Magnitsky suffered from pancreatitis and gall stones.) After he had spent almost a year behind bars, guards beat him to death. He was 37 and married with two small boys.

The incident had a transforming effect on Browder. “If Magnitsky had not been my lawyer he would still be alive,” he says. He describes Magnitsky’s death as “absolutely heartbreaking”. “If he hadn’t taken on my case he’d still be enjoying his life, being a father, looking after his wife. A young man whom I was responsible for died in the most horrific way because he worked for me.”

Browder’s memoir, published next week, recounts how Magnitsky’s death changed him from entrepreneur to global human rights crusader. Its title is Red Notice: How I Became Putin’s No.1 Enemy; and it reads like a non-fiction version of a Mario Puzo thriller. There’s a ruthless crime syndicate, a mafia boss – for Michael Corleone read Putin – and a growing tally of bodies.

Ever since Magnitsky’s murder in 2009 Browder has waged an extraordinary campaign to bring the officials to justice. Not in a court of law – there’s no prospect of a trial inside Russia – but in the wider court of international public opinion.

Facebook Twitter Pinterest Putin in the summer after talks with the Ukrainian president. Photograph: Alexander Zemlianichenko/AP

After footslogging round Washington, Browder succeeded in persuading US Congress to pass a groundbreaking Sergei Magnitsky law. The 2012 legislation imposed visa bans on the bureaucrats implicated in Magnistky’s murder. It denied them access to US banks. Putin was furious. In 2013 a Russian judge sentenced Browder in absentia to nine years in jail, and, bizarrely, “convicted” the already-dead Magnitsky. The Kremlin sent a Red Notice warrant to Interpol demanding Browder’s extradition. Interpol refused, but Moscow is currently putting together a third extradition bid.

Aged 50, and dressed in an inconspicuous suit and tie, Browder still resembles the investment banker he once was. He concedes that there are several Russians who have annoyed Putin more but says “among foreigners” he’s probably the President’s biggest foe. There have been death threats, including one sent by text days before Magnitsky died. (A quote from The Godfather Part II, sent to a colleague’s mobile, read chillingly: “History has taught us that anybody can be killed.”) Browder casually mentions that the US Department of Justice warned last summer of a plot to kidnap him and render him back to Moscow.

This may seem a little fantastical, but the Kremlin has a track record of silencing those it dislikes. Our Japanese lunch venue is a short stroll away from Mayfair and the Millennium hotel. It was there in 2006 a KGB squad allegedly poisoned the former Russian intelligence officer Alexander Litvinenko. A public inquiry into Litivineko’s radioactive murder opens this week.

Given the threats against him, I wonder why Browder is dining without bodyguards? “Bodyguards offer fake security. The real security comes from having your enemies know nothing about you,” he replies.

According to Browder, the west is embroiled in a new cold war with Russia. The most visible manifestation of this is the worsening conflict in Ukraine. But unlike in communist times, he says, the west isn’t dealing with a hostile ideology. His thesis – which I share – is that Putin and his law enforcement and spy agencies are in effect running Russia as a “criminal enterprise” for their own financial gain. Anyone who stands up to them – such as Magnitsky – faces being shot, arrested or penalised.

For those who don’t know Russia, this might sound a bit gloomy. Is it also Russophobic, the charge made by pro-Kremlin online commentators against anybody who dares to criticise Putin? Browder says his problem isn’t with Russia as such but with the powerful clique of ex-KGB spies who have grabbed the state. “I think Russia is an occupied country. There are 140 million good people and a million bad people,” he says. He points out that he is married to a Russian, Elena, (they met and fell in love in Moscow) and they have two children together. His “longest serving and most trusted” colleagues are Russian, he says, and adds: “Among the 140 million are some of the most loyal, generous and intelligent people you can find in the world.”

Browder’s own backstory is fascinating. His grandfather was the head of the American communist party in the US. As a teenager, outshone by his prodigy brother, Browder decided he would rebel by becoming a capitalist. He found himself initially drawn to London, where he worked briefly for Robert Maxwell, and later became a British citizen. He says he feels little loyalty to the US, which persecuted his leftwing family. (Senator McCarthy dragged his grandfather before the House Committee on Un-American Activities.) Browder harboured a “romantic notion” the UK was synonymous with the rule of law and freedom.

Facebook Twitter Pinterest Alexander Litvinenko after being poisoned. Photograph: Natasja Weitsz/Getty Images

After Magnitsky’s death, Browder says the policy of western governments disillusioned him. The Obama administration was deeply relectant to impose sanctions on corrupt Russian officials for fear of annoying Putin – a stance Browder calls “appeasement”. The Foreign Office treated Browder politely. But Downing Street stubbornly refused to enact its own version of the Magnitsky Law, despite strong cross-party support and worsening relations following Putin’s Crimea putsch.

The bad guys in Browder’s book are vividly painted. One of them is a senior interior ministry official called Major Pavel Karpov. Karpov sued Browder for libel in the high court and lost – the judge ruled that he had no standing in Britain. Karpov has since failed to pay £250,000 in costs. Browder says he’s dismayed at the way corrupt Russians can abuse the British legal system.

Much of Red Notice reads like a detective novel, with Browder and his lawyers trying to figure out what happened to the stolen cash. Gradually, they put together the clues. They discovered that Karpov was part of a wider group of dodgy bureaucrats. It included another interior ministry official, Lt Col Artem Kutznetsov. And the head of a Moscow tax office, Olga Stepanova.

Alexander Perepilichny, who collapsed and died suddenly. Photograph: Public domain

Between them the gang splashed millions of dollars on cars, Moscow real estate and flats in Dubai. Browder’s investigation got a “huge breakthrough” when a Russian holed up in Surrey, Alexander Perepilichny, gave them printouts from Stepanova’s Swiss bank account. (Perepilichny did business with Stepanova, and fled to the UK when they fell out.)

In 2013, Perepilichnyy suddenly collapsed and died jogging outside his Surrey mansion. He was 44 and in good shape. Browder immediately wrote to Surrey police and told them Perepilichny had been receiving death threats. Detectives failed to reply. The police carried out a toxicology analysis on his corpse 22 days later – by which time they were unable to find a cause of death. Browder is convinced that a Moscow assassin bumped off Perepilichny, just like Litvinenko. “I’m certain he was murdered. The police kicked it into the long grass. This is a travesty of justice,” he says.

It’s hard to disagree with Browder’s gloomy analysis of the current Russian regime but I point out that between 2000-2005 he was an ardent Putin supporter. He tells me: “I got it wrong. Putin is a totally inscrutable guy. He gives nothing away. People interpreted what they wanted to see in him.” He thinks Putin’s rule will last another “one, two, five years” before he is driven out, possibly by a coup. Western sanctions and the collapse of the rouble – it’s lost 50% of its value since last year – make Putin’s ruling system unviable, Browder thinks. “It’s based on 90% bribery and 10% repression. He has now run out of money for bribery, so he has to flip it over to 90% repression. I don’t think he [Putin] has got the infrastructure to be a proper repressive dictator.”

Interestingly, Browder says he opposes western sanctions on ordinary Russians, regarding them as an imprecise tool that punishes the wrong people. Rather, he would like to see the top 1,000 Russian government officials banned from Europe and the US. Of London, he says: “Every Russian wants to come here. It’s their bolthole, their escape valve.” He adds: “We have lots of leverage.”

Browder says writing the book – his first – was the “hardest thing I ever did”. It took him 18 months, with the manuscript penned in a succession of planes and trains. He had a collaborator and sent early drafts to his wife and 18-year-old son, David. “My son would say it’s boring,” he jokes. He hopes his memoir will reach a new audience. “Everything is about the story,” he says.

We finish our fried squid and marinaded sea bass. Browder says he has to leave. He’s off to Davos. There he will, once again, tell the “biblical” story of Sergei Magnitsky – a decent man who fell among thieves – to opinion formers and heads of state. His book, he admits in the final chapter of Red Notice, is a kind of macabre insurance policy. He writes: “If I’m killed, you will know who did it. When my enemies read this book, they will know that you know.”

Red Notice: How I Became Putin’s No.1 Enemy is published on 5 February by Transworld

Out in the cold: Vladimir Putin’s biggest enemies

1 Barack Obama Putin’s enmity towards Obama is ideological rather than personal. Putin’s KGB worldview is predicated on anti-Americanism: he views Moscow as a rival “superpower” to Washington, in terms of global reach and influence. Since Putin’s “return” as president in 2012 hostile rhetoric about America has hit record levels.

2 Mikhail Khodorkovsky Putin arrested Khodorkovsky – at the time Russia’s wealthiest man – in 2003 and packed him off to jail in Siberia. After a decade behind bars, he was unexpectedly freed by Russia’s president. In the event that Putin steps down from power, Khordorkovsky could play a major role in Russian politics. At least, this is the fantasy among Russia’s liberals.

3 Alexei Navalny The Moscow opposition leader is currently under house arrest. A court recently jailed Navalny’s brother on charges widely seen as fictitious: a sure sign that Navalny’s campaign against corruption and Putin’s leadership has got the Kremlin rattled. Navalny is a tall, charismatic lawyer with nationalist views and a popular blog: plenty of reasons for the authorities to shut him up.

4 Bill Browder Browder’s lobbying campaign following the murder of his lawyer Sergei Magnitsky has been extraordinarily successful, with the US and others banning the officials involved. Corrupt Russian bureaucrats have assets (and very often families) in the west. Without visas they can no longer enjoy them.

5 Petro Poroshenko The pro-western president of Ukraine is in effect at war with Putin, who last year seized a large chunk of Ukraine – Crimea – and fomented a separatist rebellion in eastern Ukraine. Poroshenko says Russia has waged a covert invasion of his country, with troops, tanks and heavy weapons. Putin denies this.

Facebook Twitter Pinterest Boris Berezovsky. Photograph: Dominic Lipinski/PA

And two dead ones ...

Boris Berezovsky Once Putin’s close friend – they went on holiday together in the south of France – Berezovsky became the president’s biggest enemy when the two fell out in 2000. Berezovsky decamped to Britain where he led a noisy campaign against Putin, accusing him of numerous misdeeds. Berezovsky was found hanged in his Surrey mansion in 2013.

Alexander Litvinenko An FSB officer, Litvinenko fled to London and worked for both Berezovsky and MI6. In 2006, two Russians – Dmitry Kovtun and Andrei Lugovoi – allegedly poisoned him with radioactive polonium in a Mayfair hotel. Afterwards, Putin said Litvinenko was too insignificant to be worth murdering. But the British government believes the Russian state killed Litvinenko in a carefully crafted plot.

Facebook Twitter Pinterest Alexei Navalny. Photograph: Pochuyev Mikhail