The June 11 announcement by Vladimir Kolokoltsev was a stunning turnaround in the case and was hailed many reporters in Russia and elsewhere who were incensed by Golunov's arrest and who believed that he had been charged in retaliation for his reporting.

Golunov left the headquarters of the Interior Ministry's Main Investigative Directorate in Moscow after he was handed a copy of the ruling terminating the criminal case against him.

He had been arrested on June 6 on charges of attempting to sell a large amount of illegal drugs.

Golunov, who had strenuously denied the charges against him, tearfully thanked a crowd of cheering supporters and journalists gathered outside the building and said that he would continue investigative reporting.

"Thank you very much for all the support," Golunov told the crowd. "I am happy that justice has been served and that the criminal case was dropped. I hope the investigation will continue and I hope that no one will find himself in the same situation that I did."

His lawyer said he had been beaten, suffering bruises, cuts, a concussion, and a broken rib during or after his arrest.

In the statement announcing Golunov’s release, Kolokoltsev said that police officers involved in the arrest had been suspended and an internal investigation into their actions had been launched.

Kolokoltsev said that the decision to drop the charges was based on results of forensics tests and "due to the fact that the alleged crime has not been proven."

Golunov was reportedly scheduled to be released later on June 11.

The arrest of the 36-year-old reporter on June 6 outraged many Russian reporters.

As a reporter for the Latvian-based Russian online news site Meduza, Golunov had gained renown for investigating corruption among top Moscow city officials and others.

Meduza's editors and others said Golunov's arrest may have been specifically due to his reporting.

'Simple Solidarity'

Aleksei Navalny, the anti-corruption lawyer and political activist, said the authorities' U-turn had been forced by the wave of public protest.

"It's just wonderful news. It's an inspiring and motivating example of what simple solidarity with people who are persecuted can achieve," Navalny wrote on Twitter.

The announcement about charges against him being dropped came a day before a march in Moscow was announced by his supporters.

Nearly 25,000 people had signed up to a Facebook page expressing their intention to attend the march.

His arrest prompted three leading non-state newspapers -- Vedomosti, Kommersant, and RBK – to publish identical front pages on June 10 that questioned the motives behind the move.

The European Union welcomed Russia's decision to drop the charges against Golunov as a "positive outcome," but demanded a probe into reports he was beaten.

"The decision to drop the charges of 'illegal production or sale of drugs' against investigative journalist Ivan Golunov is a positive outcome to this particular case," a spokesperson for the EU foreign policy chief Federica Mogherini said in a statement.

The Paris-based Reporters Without Borders media watchdog hailed "the historic mobilization" of Russians that it said made authorities drop the charges.

"We hail the historic mobilization of the Russian civil society," it said on Twitter. "Now those who tried to set him up must be judged."