Russian authorities have blocked many websites selling falsified medical documents since the start of the year, the prosecutor general's office said on Thursday.
New regulations in Russia restrict the activities of people who have not been vaccinated against Covid-19, or require them to show proof they have been tested for the disease.
Of more than 200 websites blocked since the beginning of 2021, many sold fake documents, with some generating the codes that are required for people to be able to enter restaurants in Moscow, for example, according to the prosecutor general's office.
The QR codes are a digital proof that citizens have been vaccinated and they are supposed to be downloaded from a government-run site.
However, this is impossible for people from abroad who are not registered in the Russian health-care system.
Many Russians have also complained that the system is beset by technical shortcomings.
Meanwhile the country has announced record daily new infection rates and record number of deaths, due to the rapid spread of the Delta variant of Covid-19, first detected in India.