Mikhail Lesin, a former aide to Russian President Vladimir Putin who helped found the English-language news service Russia Today, was found dead in an upscale Washington hotel room, Russian authorities said. He was 57.

The Russian Embassy in Washington on Friday confirmed the death of Lesin, whose body was discovered Thursday.

Russia Today reported on its website that Lesin died of a heart attack, and the state news agency RIA-Novosti cites a family member giving the same cause of death.

Metropolitan Police Department spokesman Officer Sean Hickman said that officers were called to the Dupont Circle Hotel on Thursday morning and found a man dead. Russian Embassy spokesman Yury Melnik confirmed that the man was Lesin.

Lesin pushed for establishing the Russia Today satellite TV channel, later renamed RT, once saying that Russia "must do propaganda for ourselves, otherwise we'll always look like bears." RT credited Lesin with "inspiring the creation" of the agency.

Since its 2005 inception, RT has become widely watched internationally but frequently criticized as a mouthpiece for the Kremlin and for presenting highly skewed reports.

Lesin served as Russian press minister from 1999 to 2004 and presidential media adviser from 2004 to 2009, RT said. He then became a senior executive at Gazprom-Media, Russia's largest media holding company.

Russian President Vladimir Putin on Saturday said Lesin made great contributions to "modern Russian mass media," Russian news agencies said.