Russia's most powerful mercenary, Yevgeny Prigozhin, has said that he asked prosecutors to investigate whether senior Russian defence officials committed any "crime" before or during the war in Ukraine.
Mr Prigozhin's request is his most blatant public challenge to date against President Vladimir Putin's top military brass, Defence Minister Sergei Shoigu and Chief of the General Staff Valery Gerasimov.
The 61-year-old restaurateur-turned-mercenary has spent months insulting both Mr Shoigu and Mr Gerasimov, who are leading Russia's war effort, for alleged treachery. Neither has responded publicly to his criticism.
"Today I have sent letters to the Investigative Committee and the Prosecutor's Office of the Russian Federation with a request to check on the fact of the commission of a crime during the preparation and during the conduct of the SMO (Special Military Operation) by a host of senior functionaries of the Defence Ministry," Mr Prigozhin said.
"These letters will not be published due to the fact that the investigative authorities will deal with this."
The defence ministry declined immediate comment.
'Putin's butcher'
Mr Prigozhin, the founder of the Wagner mercenary group, is the most striking member of Mr Putin's circle to gain widespread notoriety during the 15-month war in Ukraine.
He quipped last week that his nickname should be "Putin's butcher" rather than "Putin's chef".
He says loyalty to Mr Putin is part of his political stance, which he summed up as: "I love my motherland, I serve Putin, Shoigu should be judged and we will fight on."
In statements this week, he said he continued to inform the top leadership of the country about problems and slammed senior Kremlin officials for blocking media coverage of him and his private army.
Mr Prigozhin is not directly challenging Mr Putin but rather playing a jester role and acting with the approval of those dismayed by the military's conduct of the war, officials, diplomats and analysts said.
Mr Prigozhin's private army has been fighting alongside Russia's regular forces in Ukraine and spearheaded the months-long assault on the eastern city of Bakhmut which fell earlier this month.
UN tries to save Black Sea grain deal
The UN has proposed that Kyiv, Moscow and Ankara start preparatory work for the transit of Russian ammonia through Ukraine as it tries to salvage a deal allowing safe Black Sea grain exports, a source close to the talks said on Wednesday.
As the preparatory work starts, the UN wants parallel talks to be held on widening the Black Sea deal that was agreed last July to include more Ukrainian ports and other cargoes, said the source, who spoke on condition of anonymity.
Russia agreed this month to a two-month extension of the deal but has said the initiative will cease unless an agreement aimed at overcoming obstacles to Russian grain and fertiliser exports is fulfilled.
Ukraine and Turkey have agreed to the new proposal, intended to improve operations in the Black Sea grain export corridor, but Russia has not yet responded, the source said.
UN spokesperson Stephane Dujarric, asked about the deal at a daily press briefing, said conversations were continuing.
"As you recall, the Secretary General had put forward some ideas to the parties to improve the facilitation of the work of the Joint Coordination Centre, to also work on the issue of ammonia export, which is part of the deal that was signed," Mr Dujarric said.
"Those conversations and contacts are continuing. But that's as much as I'll say right now."
The UN and Turkey brokered the Black Sea Grain Initiative between Moscow and Kyiv last July to help tackle a global food crisis aggravated by Russia's invasion of Ukraine, a leading global grain exporter.
ABC/wires
