"I have not had communications with Mr. Bout for at least two weeks", Tarasov said. "There was a problem that developed sometime last week, but we have not been able to get in touch with Mr. Bout yet".
Bout wrote in a letter on 23 July that 36 COVID-19 cases have been registered in Marion prison in the US state of Illinois, where he is located. The US Federal Bureau of Prisons in a recent update said there are now 78 confirmed cases of COVID-19 at the facility.
Tarasov also said there was "some issue" with Bout’s communication with the family. The defence attorney added that they will try to organize a prison phone call this week or next week.
On Saturday, Bout’s wife Alla said that neither she nor the Russian Embassy in the US has been able to reach him since 22 July.
Last month, Bout told his lawyer there were no cases in his specific prison unit, which is completely isolated from the outside world and allows no visitation.
In 2008, Bout was detained in Thailand on a US government request as a result of a sting operation by the US special services. Bout was then transferred to the United States where a court found him guilty of conspiring to kill US citizens and of supporting terrorism.