Pavel Karpov, a former Russian Interior Ministry investigator who is on the so-called Magnitsky list of people barred from the US over the lawyer’s death, was suing Browder over four videos and two articles linking Karpov to the case.
Magnitsky, who was acting for Browder and his Hermitage Capital Management at the time, was arrested after accusing Russian officials of a $230m fraud, and died in prison in suspicious circumstances in 2009.
In yesterday’s High Court judgement, Mr Justice Simon said: “I have concluded that these proceedings should be struck out as abuse of the (court) process.”
The judge also found that there was “a degree of artificiality” about Karpov trying to protect his reputation in Britain.
Magnitsky was posthumously found guilty of tax evasion by a Moscow court in July this year and Browder was convicted in absentia and sentenced to nine years in jail in the same trial, which was criticised by both the US and the EU.