Mourners gathered at a cemetery just outside Moscow on Thursday to pay their respects to Dmitry Utkin, the shadowy Wagner commander killed alongside the group's chief in a plane crash last week.

Utkin, a veteran of Russia's GRU military intelligence division, was beside Wagner leader Yevgeny Prigozhin on the plane on August 23 when it went down, killing all on board.

Since Thursday morning, police have cordoned off the Mytishchinsky memorial complex - a vast military cemetery dotted with groves of trees and red granite stone.

Several muscular men with tattoos gathered at the entrance with bouquets of red roses, before a motorcade carrying Utkin's coffin drove into the cemetery.

Little is known publicly about Utkin, 53, who was responsible for commanding Wagner's military operations while Prigozhin took care of finances and relations with the Russian state.

Prigozhin, 62, was buried on Tuesday in a private ceremony in his native Saint Petersburg.

Moscow used Wagner's forces to wage some of the Ukraine conflict's bloodiest battles, including a devastating, months-long offensive that left the eastern city of Bakhmut in ruins.

Utkin was also believed to have taken part in Wagner's short-lived mutiny in June, when the group marched towards Moscow, demanding the army chief of staff and defence minister be sacked.

The funeral ceremony began at about 10 am (0700 GMT) in St Sergius, a traditional white church on the memorial complex, where about 20 of Utkin's loved ones were present.

Access to the cemetery grounds was reserved to those on a list drawn up personally by Utkin's wife, to the discontent of some visitors trying to get in.

A man in dark glasses, with his face covered by a black scarf, approached a group of men with flowers and asked: "Does anyone have guns with them?" 

"No no, we left everything," they answered.

Speculation that the Kremlin may have been involved in last week's crash has been rife, with the incident coming exactly two months after Wagner staged its rebellion.

The Kremlin dismissed the rumours as "an absolute lie."

The Kremlin said Wednesday that investigators were probing all possible scenarios surrounding the incident, including that it was "premeditated".