Russian investigative journalist Ivan Golunov has been charged with trying to illegally sell drugs, prominent rights lawyer Pavel Chikov says.
He says Mr Golunov became ill at a Moscow police station, but doctors were not allowed in for some time. Russian officials have made no public comments.
The 36-year-old reporter for the Latvia-based news site Meduza was held by police on Thursday.
His lawyer says drugs were planted on him, but the authorities deny this.
Meduza says he is being “being persecuted because of his journalistic activity”.
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What’s the latest?
Mr Golunov was officially charged on Saturday morning, Mr Chikov said.
He added that a doctor examined the reporter and found he had “a suspected rib fracture, concussion and haematoma”. The reporter also needed to be taken to hospital.
The Russian authorities have not commented on this.
Mr Golunov appeared handcuffed in a video clip posted to social media on Friday night. He said he was involved in “scuffles” with police, showing bruises.
He has repeatedly exposed corruption among Moscow’s high-profile businesspeople and its political elite, as well as fraudulent financial schemes in the city.
How have media and activists reacted?
“We will find out by whose will Vanya [Ivan] is being pursued, and we will make this information public,” Meduza’s director Galina Timchenko and editor Ivan Kolpakov said.
“We will protect our journalist by all available means.”
They added that Mr Golunov had received threats over the last few months, in connection with an as-yet-unpublished story he had been working on.
His arrest sparked protests in Moscow and St Petersburg, and more than a dozen people – mostly fellow journalists – were reportedly detained and later released.
In recent years many opposition figures and human rights activists in Russia have been detained on apparently fabricated drugs charges, which are widely seen as an attempt to quash political dissent.
How was Ivan Golunov arrested?
He was on his way to meet another journalist on Thursday when he was stopped and searched by officers.
They claim they found the synthetic drug mephedrone in his rucksack, and that a later search of his flat turned up more drugs and some scales – indicating that he was involved in dealing.
Meduza said he was beaten up by officers both during his arrest and later at the police station.
He was only able to contact a friend after 14 hours, the statement added.
In the first video of Mr Golunov since his arrest, posted by the Russian news site Breaking Mash, he lifts up his shirt to reveal what appear to be carpet burns on his back.
Mr Golunov’s lawyer, Dmitry Julay, told reporters that he had been denied food and sleep for more than 24 hours.
BBC Russian journalist Olga Ivshina reports that police released photos they claimed showed drug paraphernalia in Mr Golunov’s flat, but these were later withdrawn.
The police, she adds, admitted that “most of the published photos had not been taken at Mr Golunov’s flat after all, but were related to another criminal investigation that might be linked to his detention”.
Journalists in Russia have often been harassed or attacked in recent years for their work.
Much of Russia’s media is controlled by the state and Russia is ranked 83rd out of 100 countries for press freedom by Freedom House.