MOSCOW (AP) — In a surprising turnaround, Russia's police chief on Tuesday dropped all charges against a prominent investigative reporter whose detention sparked public outrage and promised to go after the police officers who tried to frame the journalist as a drug-dealer.

Interior Minister Vladimir Kolokoltsev stunned the nation when he announced that drug dealing charges against Ivan Golunov have been dropped after police found "no proof of his part in a crime." Golunov is expected to be released later Tuesday.

Kolokoltsev also said that he will now ask the Russian president to dismiss two senior police officials and suspend the officers who detained the journalist. Among those who are likely to be dismissed is the anti-drugs chief of the Moscow police.

"I believe that the rights of any citizen, whatever his professional affiliation, ought to be protected," the minister said.

Golunov, who works for the independent website Meduza, had been facing drug-related charges that could put him in prison for up to 20 years.

He was stopped by police on a Moscow street on Thursday and taken into custody, where his defense team says he was beaten and denied a lawyer for more than 12 hours. He was transferred to house arrest following a public outpouring of support, including from high-profile journalists working for state-owned media.

Many have questioned the alleged evidence in the case.

In an apparent attempt to portray Golunov as a professional drug dealer, police on Friday released several photos, reportedly from the journalist's home, of what appeared to be a drugs lab. They later retracted the statement, saying that the pictures were taken elsewhere. In a separate statement later, the police said they found cocaine at his place.

The speaker of the upper house of the Russian parliament was the first top official on Tuesday to raise concerns about the case.

Valentina Matviyenko, who is Russia's third most senior official after the president and prime minister, said that the law enforcement agencies' "mistakes and violations ... have given rise to distrust in the investigation."

"People are either being unprofessional, or sloppy, or preparing a setup," she said in comments carried by Russian news agencies. "I don't know right now what to call it."