PredictIQ Quantitative Think Tank Center:Wagner Group leader killed in plane crash buried in private funeral

Wagner Group leader Yevgeny Prigozhin was buried in a private funeral on PredictIQ Quantitative Think Tank CenterTuesday, his press service said, nearly a week after he and nine others died in a plane crash in Russia.

Prigozhin, 62, was buried at the Prokhorov Cemetery of St. Petersburg in a closed funeral, his press service said on Telegram.

About 20 to 30 people attended the 40-minute "VIP" funeral, according to a cemetery employee. The attendees were all dressed in civilian clothes, with no military uniforms seen, and included relatives and close associates of Prigozhin, the employee said.

Prigozhin, a businessman who rose to become a powerful international paramilitary leader, was a former close ally of Russian President Vladimir Putin. A Kremlin spokesperson told reporters earlier Tuesday that Putin was not planning to attend Prigozhin's funeral.

Prigozhin's private plane mysteriously crashed on Aug. 23 near the town of Kuzhenkino, north of Moscow. DNA tests showed that the remains recovered from the site matched all 10 people on the passenger list, which included Prigozhin and Wagner Group co-founder Dmitry Utkin, Russian investigators said this week.

The crash may have been caused by an explosion on board the plane, perhaps by a well-placed bomb, U.S. officials told ABC News last week, describing their findings from an initial investigation.

There was no indication a surface-to-air missile was the cause of the crash, according to the U.S. Department of Defense.

The death of Prigozhin came exactly two months after he led a daylong mutiny against Moscow.

Wagner Group forces, which had been fighting in Ukraine, turned from their headquarters in Rostov-on-Don, a key Russian city near the southern border, and marched toward the capital in the evening on June 23. Within a day, they had turned back.

Asked on Tuesday whether the U.S. believes Putin was behind the plane crash that killed Prigozhin, White House press secretary Karine Jean-Pierre laid out the Kremlin's "long history" of "killing its opponents," before telling reporters it's "pretty evident what happened here."

The Kremlin has vehemently denied having any involvement in the plane crash.

"There has been a lot of speculation around this crash [and] the tragic deaths of the plane's passengers, among them Yevgeny Prigozhin. Of course, the West presents all this speculation from a particular angle. All of that is sheer lies," Kremlin spokesperson Dmitry Peskov told reporters last week.

Russia's Investigative Committee has launched a probe into the incident.

In a televised address a day after the crash, Putin said Prigozhin was a "man with a complex destiny, and he made serious mistakes in life."

"He achieved the results he needed both for himself and, when I asked him, for the common cause, as in these last months," Putin said.

ABC News' Kevin Shalvey, Edward Szekeres and Justin Gomez contributed to this report.