Ukrainian intelligence has released a tapped telephone conversation that it said showed a pro-Russian rebel leader agreeing to dump the body of a local councillor and "Ukrainian patriot" whose murder has triggered a security offensive in the east.
"Slava, please sort out this stiff ... It's lying here, stinking," says a man whom the Ukrainian SBU security service identified as a Russian agent.
The SBU said he was talking to Vyacheslav Ponomaryov, the self-declared mayor of Slovyansk, the rebel military stronghold in Donetsk region.
"The body? Yeah, I'm just finishing up with the journalists and I'll take care of it," the man identified as Ponomaryov replies. "I'll go sort out burying that big mouth."
Ponomaryov could not be reached for comment.
The voice sounded similar to his but there was nothing in the comments to link them directly to the murdered politician, Volodymyr Rybak. A town councillor from the prime minister's party, Rybak was kidnapped last week and his mutilated body was found in a river near Slovyansk.
Another audio clip issued by the SBU featured a man it said was another Russian agent using distinctive Moscow slang to order an operative in nearby Horlivka to seize "Rybak" after the politician "made a nuisance of himself" at the town hall.
Moscow denies having forces in Ukraine. Ponomaryov, a local businessman, denies taking orders from Russia.
Rybak was confronted last Thursday by a hostile crowd, including a masked man in camouflage, after he tried to remove a separatist flag in Horlivka, where he was a councillor. That encounter was captured on video.
Rybak, whose death the acting president cited as the "murder of a Ukrainian patriot" in ordering a new offensive against Russian-speaking rebels seeking annexation by Moscow, was buried in Horlivka on Thursday. Mourners held up a Ukrainian flag.