At least 60 Russian officials implicated in the death of Moscow lawyer Sergei Magnitsky have been banned from entering Britain, The Observer newspaper reported over the weekend.
Russian President Dmitry Medvedev has promised a full inquiry into the lawyer's death.
Veteran human rights campaigner Lyudmila Alexeyeva said the visa bans were caused by lack of action on the part of the authorities at home.
Magnitsky was arrested in November 2008 on tax evasion charges shortly after alleging that officials, including law enforcement members, were involved in a $230 million tax scam.
He was detained in Moscow's notorious Butyrka prison pending trial.
Magnitsky, who was working on behalf of a British investment company, Hermitage Capital Management, died a year later after being denied medical care, aged 37.
In July, the Kremlin's rights body said Magnitsky's death was the result of "calculated, deliberate and inhumane neglect."
In August, the United States placed a visa ban on an unspecified number of officials it believed were involved in the death. Russia responded with its own blacklist of U.S. officials.
"This [the introduction of sanctions] has been caused by the absence of any steps from the Prosecutor General's Office and other authorities in response to our calls to investigate Magnitsky's case," Alexeyeva, the head of the Moscow Helsinki Group, told RIA Novosti.
"Nothing's been done, that's why we had to appeal to the West," she said.
The Observer said British government has not publicized its move for fear of damaging ties with the Kremlin.
Larisa Litvinova, chief doctor at the Butyrka prison, and the jail's deputy chief Dmitry Kratov, were charged with causing death by negligence in August.
President Medvedev's human rights council said two different officials - senior Interior Ministry investigator Oleg Silchenko and Butyrka chief Ivan Prokopenko - were at fault.