Bill Browder was arrested for two hours in Madrid on Wednesday morning.

He was deported from Russia in 2005 after exposing corruption in the country.

A Russian court sentenced him to nine years in prison last year.

Western police often ignore politicised requests from Russia to arrest people, but something changed on Wednesday.

It's not clear what happened, as local and international police don't agree on why he was taken in.



One of Vladimir Putin's most vocal critics was briefly arrested in Spain on Wednesday morning after years on the run from the Russian government — but nobody wants to claim responsibility for doing it.

Bill Browder, a US-born British citizen, was arrested in Madrid around 9:30 a.m. local time and released around 11:30 a.m., according to his tweets. It was carried out on a Russia-issued Interpol arrest warrant, Browder said.

Browder said: "Spanish National Police just released me after Interpol General Secretary in Lyon advised them not to honor the new Russian Interpol Red Notice. This is the 6th time that Russia has abused Interpol in my case."

He also included a photo of the arrest warrant, which appeared to have been issued by the Spanish interior ministry, and claimed that Browder was wanted for fraud, the charge he has been convicted of by a Russian court.

Browder, a US-born British citizen who was at one point Russia's largest foreign investor, was deported from Russia in 2005 after exposing corruption in the country.

Russian authorities called him a threat to national security, and a Russian court sentenced Browder in absentia to nine years in prison on fraud and tax evasion last year.

Moscow is keen to have Browder back in the country: It has issued six requests to Interpol to arrest and extradite him, Browder said, but the international agency has routinely ignored those requests in the past.

It's not exactly clear why Browder was arrested on Wednesday.

The Spanish national police told Business Insider the arrest came a search and seizure warrant from Interpol, a global agency which facilitates requests by police forces to share information or make arrests in other countries.

However, in a statement Interpol denied ever having an arrest warrant out for Browder.

Vladimir Putin has been chasing after Browder for years. Getty Images

A spokeswoman for Spain's National Police Corps told Business Insider on Wednesday morning that Madrid police thought they were acting on Interpol instructions.

She said: "William Browder was arrested after an Interpol Search and Seizure warrant was issued. Agents have confirmed that this warrant/order is no longer valid and he has been freed."

The spokeswoman did not mention who issued the arrest warrant, also known as a Red Notice, and declined to provide updates on the arrest warrant.

Meanwhile, a spokesman for Interpol told Business Insider:

"There is not, and never has been, a Red Notice for Mr Bill Browder.

"Mr Browder is not wanted via INTERPOL channels and we would advise you to contact the Spanish authorities for any information about the basis of the reported arrest made today."

Business Insider has requested clarification from Interpol.

Browder's lawyer, Sergei Magnitsky, was put in pretrial detention, tortured, and killed in Russian custody in 2009.

Browder has since been campaigning for international sanctions on Russia, named the Magnitsky Act.