WASHINGTON — The police here said on Saturday that the department was continuing an investigation into the death of Mikhail Lesin, a former aide to President Vladimir V. Putin of Russia who helped design the government’s takeover of independent media in that country. Mr. Lesin was found in a high-end hotel here on Thursday morning.

Mr. Lesin, who the police said was 59, was found with no signs of life about 11:30 a.m. in a room at the Dupont Circle Hotel. He was identified by an official from the Russian Embassy here on Friday, according to its press secretary, Yury Melnik.

As of Saturday, the police said, an autopsy had been conducted but no ruling had been made about the cause of death. Russia Today, the English-language state television network Mr. Lesin helped found, reported that he had died of a heart attack, a detail echoed by a member of Mr. Lesin’s family who reportedly spoke with the state news agency RIA Novosti.

The hotel deferred all comment on Saturday to the police in Washington.

Mr. Lesin was a major figure in Russian media after the fall of the Soviet Union, first as an advertising executive and later as a top government official and media executive.