A Russian investigative journalist facing drugs charges in case supporters have denounced as a frame-up was taken to the hospital Saturday after complaining of being beaten in police custody.
Ivan Golunov, a Moscow-based reporter for Meduza independent news site has been charged with attempted dealing in designer drug mephedrone and cocaine.
Supporters and his defense team said he had received death threats and suggested the drugs were planted to punish him over his reporting.
Rights groups Amnesty said there was evidence that the authorities were fabricating drugs charges to shut up their critics.
After his detention on Thursday Golunov told a representative of Russia's presidential rights council, which advises Vladimir Putin that police had punched him and stood on his chest, His lawyer Pavel Chikov said that paramedics suspected he had broken ribs and concussion.
A paramedic who examined him told Interfax news agency that he had numerous grazes to his chest, injuries to his ribs and a suspected head injury while police have denied he was beaten.
The journalist was due to attend court Saturday for a ruling on whether to hold him in custody but police said that they called an ambulance after he complained of feeling unwell and he was taken to a hospital for examination.
Golunov's detention has prompted widespread outrage and supporters and journalists have held protests outside the police headquarters and the court where his case was due to be held.
Meduza posted photographs of people holding placards in support of Golunov in cities in Russia and abroad.
The 36-year-old has investigated high-level corruption among Moscow officials and Meduza said it believed he was being persecuted for his journalistic work.
Meduza general director Galina Timchenko told journalists outside court that Golunov had received death threats over his reporting.
"Ivan received threats. Two months ago they became almost daily," she said. She had failed to persuade Golunov to contact police, she added.
"They said 'we'll bury you forever'," she said.
Golunov has investigated everything from Russia's shady funeral industry to corruption in Moscow city hall.
"We have reasons to believe that Golunov is being persecuted for his journalistic work," Meduza said in an earlier statement.
The respected site is based in EU member Latvia to avoid Russian censorship, but some journalists, including Golunov live in Russia.
One of his lawyers, Dmitry Dzhulai, told AFP it appeared the drugs had been planted on Golunov.
Moscow police admitted that they published on their website photographs of drugs paraphernalia that they captioned as showing the crime scene but were not taken at Golunov's flat.
"Everything indicates that the authorities are planting drugs on their targets to shut them up with a jail sentence," said Natalia Zvyagina, director of Amnesty International's branch in Russia.
A presidential rights council member who visited Golunov in detention on Friday, Yeva Merkacheva, said in a statement that Golunov had shown her scratches on his back that he said were from police dragging him.
He also told her he was twice punched in the head and that the police also stood on his chest and that "he hadn't slept for 24 hours and so he feels bad. He also hasn't eaten", she said.
Russian journalists and rights groups see the case as an example of the persecution of independent reporters, with many saying Golunov was not known to take drugs.
Outside the Moscow court where Golunov was due to appear Saturday, several journalists held up placards with slogans including "I am the journalist Ivan Golunov. Arrest me too."
Police detained three people, an AFP video journalist saw.
On Friday, dozens of journalists protested against Golunov's detention outside Moscow police headquarters and were themselves briefly detained.
Reporters Without Borders warned his arrest could mark "a significant escalation in the persecution" of independent journalists in Russia.
While journalists at Russia's dwindling number of independent media resources frequently face criminal probes, physical attacks and official pressure, drugs accusations are not common.