The Kremlin’s spokesman says his son fought in Ukraine.

The Kremlin’s spokesman, Dmitri S. Peskov, said on Monday that his son had fought in Ukraine, highlighting the Moscow elite’s uneven participation in a war effort that has so far cost the lives of tens of thousands of Russian soldiers.

Mr. Peskov’s remarks came after Yevgeny V. Prigozhin, the leader of Russia’s Wagner private military company, said on Saturday that Mr. Peskov’s son had served as an artilleryman with his mercenary group for six months. The son, Nikolai Peskov, 33, described his purported service to Komsomolskaya Pravda, a pro-government newspaper, in an article published the next day.

On Monday, Mr. Peskov, President Vladimir V. Putin’s longest-serving chief spokesman, was asked about his son at a daily press briefing.

“It is true, he did take part in the special military operation,” he told journalists, using the government’s euphemism for the war in Ukraine. He declined to provide further details.

None of the accounts could be independently verified, and it was not possible to determine whether Mr. Prigozhin was pointing out a rare example of a wealthy young Russian’s military service or was attempting a public relations stunt to needle Kremlin insiders.

Mr. Prigozhin, a social media provocateur, has often criticized the country’s elite for weak patriotic sentiment. In March, Mr. Prigozhin claimed that the son-in-law of Russia’s defense minister, Sergei K. Shoigu, had joined Wagner. It turned out that the fighter he identified was of no relation to Mr. Shoigu, a frequent target of Mr. Prigozhin’s criticism.

Some elements of Mr. Prigozhin’s account of the younger Mr. Peskov’s service sounded like trolling.

Mr. Prigozhin said that in Wagner, Nikolai Peskov had worked loading ammunition on an assignment that would have placed him miles behind the front line. He also said that Nikolai Peskov stood out from his comrades because he spoke English and “looked too clever.”

Several acting and former Russian officials have volunteered for the military since the start of the invasion last year, using their service to bolster their nationalist credentials on social media.

But it has been difficult to confirm details of their service, including whether they served in frontline roles.

In 2011, Nikolai Peskov posted photos on social media that appeared to show him participating in Russia’s obligatory one-year military service.

Since Mr. Putin ordered the full-scale invasion of Ukraine last year, the younger Mr. Peskov has been goaded about further enlistment. Shortly after Mr. Putin announced in September that he would mobilize 300,000 men to fight, opposition activists claiming to be conscription officers prank-called him.

“Obviously, I won’t come,” a man described Nikolai Peskov told the prank callers after being asked whether he would report to the conscription office the next day. “I’m going to resolve this on a different level.”

But he told the Komsomolskaya Pravda newspaper that joining Wagner was his decision, saying that he had received a medal “for bravery.”

He did not immediately respond to a request for comment from The New York Times.

Oleg Matsnev and Alina Lobzina contributed research.