London-based investor and prominent Kremlin critic Bill Browder told CNBC that his arrest in Madrid on Wednesday was another attempt by Russian President Vladimir Putin to put a stop to his political activities.
"He's been going after me in every different way, trying to have me arrested, trying to have me sued, doing all sorts of crazy stuff," Browder said on "Power Lunch" Wednesday. "And today was just one more example of that."
Browder, co-founder and CEO of Hermitage Capital Management, said Spanish national police officers showed up to his hotel around 9:40 a.m. and told him they had a warrant for his arrest from Interpol, based on a Russian request.
"I don't know how they found out, but they knew I was going to be in Spain, and they tracked me down in Spain and got this organized," Browder said.
"It was all based on a Russian warrant," he added.
Browder live-tweeted the events of the day.
He said he was then taken to a police station in Madrid. After contacting Interpol, Spanish officials told Browder that Interpol was canceling the warrant, and he was released, he said.
He has since returned to his home in London.
The American-born Browder, author of the 2015 book "Red Notice," did business in Russia for more than a decade. His lawyer, Sergei Magnitsky, died in a Russian prison in 2009 after exposing corruption in the government. Since then Browder has led an anti-corruption campaign against Russian officials. In 2012, the U.S. Congress passed the Magnitsky Act, which sanctions Russians for alleged human rights abuses. Since then it has been difficult for some Russians to obtain visas to enter the U.S.
As a result, Browder said, Russian officials seek retribution.
"This is something that is front and center of Putin's mind," he said. "He absolutely hates the Magnitsky Act. He stated it as the single largest foreign policy priority to repeal it."
Last October, Canada passed its own version of the act, something Browder told CNBC he was "responsible for." Within a few days, he said, he was placed on Interpol's wanted list. Browder said he's been on the list six times, per Russian request, since 2013.
Last week the U.K.'s House of Commons passed its own version of the Magnitsky Act.
"In doing so, it ... creates a hostile environment for Putin and his cronies in London," Browder said. "And I'm sure that they're very mad about that."