A former commander with the Russian paramilitary Wagner Group has claimed asylum in Norway after deserting from the mercenary outfit.

Andrey Medvedev, 26, crossed the border into Norway last Friday, where he was detained by border guards.

He is currently being held in the Oslo area where he faces charges of illegal entry to Norway, his lawyer Brynjulf Risnes told the BBC.

Mr Risnes said his client left Wagner after witnessing war crimes in Ukraine.

The Norwegian Border Guard confirmed to the BBC that a Russian man had been detained after crossing the country's 198km (123 mile) long border with Russia, but said it could not comment further for "reasons of security and privacy".

Tarjei Sirma-Tellefsen, police chief of staff in the Norwegian region of Finnmark, said a man had been detained by a border patrol and said he had applied for asylum.

But the Russian human rights group Gulagu.net, who helped Mr Medvedev leave Russia, confirmed his identity. His escape is believed to be the first known instance of one of the group's soldiers defecting to the West.

Gulagu.net's founder Vladimir Osechkin told the BBC that Mr Medvedev had joined the paramilitary group in July 2022 on a four-month contract, but had deserted after witnessing a host of human rights abuses and war crimes while serving in Ukraine.

He said that Mr Medvedev is a former soldier in the Russian army and that he later served time in prison between 2017 and 2018 before joining the Wagner Group.

He was placed in charge of a Wagner division in Ukraine, where the mercenary group supplied him with around 30-40 troops every week, Mr Osechkin said.

In a video posted by Gulagu.net to its social media channels, Mr Medvedev said he fled Ukraine in November after being informed that the group intended to extend his contract indefinitely.

After spending two months underground in Russia, he crossed the border into Norway last week.

Mr Risnes said his client had also witnessed a host of war crimes while fighting in Ukraine, including seeing "deserters being executed" by the Wagner Group's internal security service.

"In short he felt betrayed and wanted to leave as soon as possible," Mr Risnes said.

He added that he believed Mr Medvedev had taken some evidence of war crimes with him to Norway and that he intends to share his information with groups investigating war crimes in the coming weeks.

In response, the founder of the Wagner Group, Yevgeny Prigozhin, appeared to laugh off the allegations.

In a press release from one of his companies, Prigozhin issued a sarcastic statement, linking Mr Medvedev to a non-existent Nordic mercenary unit and said he was a Norwegian citizen, in an apparent attempt to mock the man's testimony.

Prigozhin also accused him of "mistreatment of prisoners" and said that his former employee was "very dangerous". Mr Risnes told the BBC that the Wagner leader's claims were not true.

UK officials believe the Wagner Group makes up about 10% of Russia's forces in Ukraine, and played a significant part in helping Moscow's forces take the town of Soledar in eastern Donbas region last week.

Thousands of its troops have been recruited from Russian prisons. Mr Prigozhin - a former convict himself - has promised recruits their freedom in exchange for six months service in Ukraine.

Before the invasion of Ukraine, it had only a few thousand mercenaries. Most were believed to be experienced former soldiers, including some from Russia's elite regiments and special forces.

Since 2015, it is believed to have deployed troops to Syria, Libya, Mali and the Central African Republic.