Kiev (AFP) - The body of a Ukrainian lawyer representing one of two purported Russian soldiers on trial in Kiev was discovered Friday buried in a farm with signs of a violent death.

Yuriy Grabovsky defended Russian sergeant Aleksander Aleksandrov in a high-profile case that has further strained relations between Moscow and Kiev.

Ukraine alleges that Aleksandrov and fellow special operations captain Yevgeny Yerofeyev were members of the Russian armed forces when they were captured in the pro-Moscow separatist region of Lugansk in May 2015.

Russia says both had resigned from active duty before crossing into the war zone of their own free will.

But the two wounded men told reporters from their Kiev hospital beds in May that they had been sent across the border on reconnaissance missions by their Russian commanders and had been enrolled in a military intelligence unit at the time.

Attorney Grabovsky was last seen in the government-controlled southern Ukrainian port city of Odessa on March 5. He was soon reported missing and the local police launched a murder investigation on March 10.

Chief Ukrainian military prosecutor Anatoliy Matios told reporters Friday that Grabovsky's body was discovered in an abandoned farm about 125 kilometres (75 miles) south of Kiev.

Matios said the 43-year-old lawyer was "violently murdered, with an additional shot fired" to make his death certain.

The prosecutor said two suspects had been detained and one had already confessed to the crime and helped locate the lawyer's body.

"These are Ukrainian citizens, one of whom used a fake special service agent ID," Matios said.

He added that the suspects "had received a lot of money" for carrying out the killing and "did everything to create their alibis."

The accomplices allegedly drugged Grabovsky in Odessa before taking him Kiev.

Matios said the men confessed to attaching a bracelet packed with an explosive to the lawyer's leg and warning him that he would be blown up should he try to flee or report his kidnapping.

Story continues

The prosecutor did not say when or why the men then decided to drive him out of the city in order to kill him.

- 'Russophobic hysteria' -

The Russian foreign ministry Friday angrily blamed the attorney's death on the "Russophobic hysteria" allegedly being fanned by Ukraine's pro-Western leadership.

"Despite all our warning, the Kiev authorities either could not or did not want to ensure Yuriy Grabovsky's safety," the ministry said in a statement.

"Ukraine clearly does not intend to adhere to legal methods or accept that the anti-Russian and overtly Russophobic hysteria adopted by the authorities" is failing.

Prosecutors said the attorney's death would not delay a trial that Ukrainian President Petro Poroshenko said Tuesday was "in its final stage".

Poroshenko had proposed swapping the suspected soldiers for Nadiya Savchenko -- a Kiev-born helicopter pilot who was sentenced Tuesday in Russia to 22 years in prison for her alleged involvement in the killing of two Moscow reporters in the separatist east.

Savchenko denies the charges and US Secretary of State John Kerry said he called for her release during talks with Russian President Vladimir Putin in Moscow on Thursday.

One of the pilot's Russian lawyers said Friday he had also received threats while defending the 34-year-old woman known to many as Ukraine's "Joan of Arc".

"A lawyer working on a highly-publicised case easily obtains the status of an enemy of his own people," Ilya Novikov wrote on Facebook.

"I do not know if Yuriy received as many threats and insults from Ukrainians for defending Aleksandrov as we did for defending Savchenko from Russians," the pilot's lawyer said. "I suspect that he did."