SAO PAULO, Aug 29 (Reuters) - Russia has informed Brazil's aircraft investigation authority that it will not probe the crash of the Brazilian-made Embraer jet that killed mercenary boss Yevgeny Prigozhin under international rules "at the moment", the Brazilian agency told Reuters on Tuesday (Aug 29).

Prigozhin, two top lieutenants of his Wagner Group and four bodyguards were among 10 people who died when the Embraer Legacy 600 crashed north of Moscow last week.

He died two months to the day after staging a brief mutiny against the Russian defence establishment that posed the biggest challenge to President Vladimir Putin's rule since he rose to power in 1999.

Brazil's Center for Research and Prevention of Aeronautical Accidents (CENIPA), in the interests of improving aviation safety, had said it would join a Russian-led investigation if it were invited and the probe held under international rules.

Russia’s aviation authority was not obligated to say yes to CENIPA, but some former investigators said it should, as the US and other Western governments suspect the Kremlin of being behind the Aug 23 crash of the Embraer Legacy 600, which has a good safety record.

The Kremlin denies any involvement. Prigozhin was publicly critical of Moscow's prosecution of its invasion of Ukraine. The Wagner mercenaries fought battles there on Russia's side.

According to the Montreal-based United Nations International Civil Aviation Organization (ICAO), the flight from Moscow with a destination of St Petersburg was domestic, so it is not subject to international rules known throughout the industry by its legal name "Annex 13".