A former public schoolboy in Britain who Russia accuses of plotting to assassinate Vladimir Putin has been shot and wounded in Ukraine.

Adam Osmayev, 36, is fighting for his life in a Kiev hospital after being struck in the chest by a man carrying a pistol who posed as a French journalist.

The assailant was then shot and wounded with a Makarov pistol by Osmayev's wife Amina Okuyeva, 33, a female sniper from the Russian Muslim region of Chechnya.

Former British public schoolboy Adam Osmayev, right, who was accused of plotting to kill Vladimir Putin was shot and wounded by a Russian hit man known by the nickname Dingo (left)

Artur Denisultanov-Kurmakayev, known as Dingo, was carrying a fake Ukrainian passport

Dingo was shot and wounded by Osmayev's sniper-trained wife Amina Okuyeva

The gunman - who carried fake Ukrainian documents - was identified today by local media as an alleged Russian gangster nicknamed Dingo, called Artur Denisultanov-Kurmakayev, citing law enforcement sources.

Russia had attempted in vain to seek former Buckingham University student Osmayev's extradition over its claim that he had been planning a 2012 assassination of Putin in Moscow.

He had earlier studied A levels at Wycliffe College near Stroud.

Ukrainian police and secret services said they were checking for Russian traces to the Kiev shooting, say local reports.

Suspect 'Dingo' is from St Petersburg but had Ukrainian documents under the name Alexander Dakar, said Kiev reports.

Kiev had refused to extradite Osmayev to Russia, and later he and his wife fought for pro-Ukrainian forces against pro-Vladimir Putin rebels in the east of the country.

The assailant, also now in hospital, had Ukrainian documents with him.

Ukrainian police believe Dingo shot Osmayev with the pistol on the left, while Osmayev's sniper-trained wife returned fire with this Russian-made Marakov pistol, right

Osmayev, who is from a wealthy Chechen family, is a vocal critic of Vladimir Putin as well as Chechnya's eccentric pro-Kremlin hard-man leader Ramzan Kadyrov

Osmayev is from a wealthy Chechen family, and is a foe of pro-Putin ruler Ramzan Kadyrov.

He claimed he had been injected with drugs and tortured to extract a confession that he planned to kill Putin and Kadyrov.

His confession was 'the result of physical and psychological pressure which the law enforcement services put me under since the moment I was detained,' he said.

He was beaten so badly, he could not stand for two months, he claimed.

Moscow claimed he intended to blow up Putin's motorcade in the Russian capital.

Ukrainian police are investigating the attempted assassination of Osmayev. Kiev has repeatedly refused to extradite the Chechen to Moscow to face trial for plotting against Putin

Both injured men were hospitalised and in a stable condition on Friday with police saying the attacker would be able to testify.

Officers said that the attacker carried a Ukrainian passport in the name of Alexander Dakar.

Anton Gerashchenko, adviser to the minister of internal affairs, wrote on Facebook that the crime could have been 'prepared in advance by a killer sent to Ukraine by Russian special services'.

Osmayev spent years in prison in Ukraine after being accused in 2012 over a bizarre plot to assassinate Putin, then a presidential candidate, by bombing his motorcade.

The plot was reported on state television in Russia just days before the presidential elections. A second suspect Ilya Pyanzin, a citizen of Kazakhstan, was extradited to Russia and jailed for 10 years.

Osmayev was detained in the Ukrainian city of Odessa and made a confession that he later said was extracted under torture.

He spent almost three years in prison but was convicted only of illegal possession of explosives and was never extradited to Russia.

Osmayev was released soon after Ukraine's pro-European revolution in 2014 and at the beginning of the separatist conflict in the east of the country joined a volunteer battalion to oppose the pro-Russian rebels.

Osmayev, who was reportedly born in the Chechen capital of Grozny, does not have Ukrainian citizenship, Gerashchenko said.