The chief of mercenary group Wagner on Wednesday accused Moscow's top brass of deceiving Russians about the course of Ukraine's offensive and pointed to Kyiv's progress on the battlefield.
Early this month Kyiv's military launched its counteroffensive in the east and south of the Western-backed country in an effort to claw back territory lost since last year.
Russian President Vladimir Putin has repeatedly said that Ukraine's offensive is failing.
But Wagner chief Yevgeny Prigozhin, whose forces had for months led an assault for towns in eastern Ukraine including Bakhmut, accused the Defense Ministry of not telling the truth and losing territory to Ukrainian troops.
"They are misleading the Russian people," he said in an audio message released by his spokespeople.
A number of villages including Pyatykhatky has been lost, Prigozhin said, pointing to a lack of arms and ammunition.
"Huge chunks have been handed over to the enemy," he said, adding that Ukrainian troops have already sought to cross the Dnipro River, a natural border on the frontline.
"All of this is being totally hidden from everyone," the 62-year-old said.
"One day Russia will wake up to discover that Crimea too has been handed over to Ukraine," he said.
Kyiv has reported modest gains, retaking eight settlements in the first cautious steps of a fightback against entrenched Russian positions.
On Wednesday, Putin insisted again that Ukrainian troops had sustained "serious losses" and said that there was a "certain lull" on the front.