US media reported in July that Richardson planned to travel to Russia in an attempt to negotiate the release of WNBA basketball player Brittney Griner, who was convicted in a Russian court for carrying cannabis oil in her luggage.
The report said on Tuesday evening that Richardson and his team held meetings with senior Russian officials.
The report also said that the details about the meetings were not clear at present.
Richardson is known for being dispatched on several occasions to negotiate the release of Americans detained overseas.
Richardson's office did not immediately respond to Sputnik's request for comment on the matter.