A wealthy Armenian businessman based in Russia has been detained over alleged links with a notorious Russian criminal gang, according to media reports.

The Rosbalt news agency said Levon Hayrapetyan was detained at Moscow's Domodedovo Airport on July 15 as he was returning from Monaco.

Hayrapetyan, a native of Azerbaijan's rebel region of Nagorno-Karabakh, is known for his investments and charity projects in that breakaway territory, including a grand wedding for 700 couples there in 2008.

He is believed to be one of the wealthiest Armenian businessmen in the world.

Rosbalt says he is suspected of having ties with a criminal gang led by Sergey Finagin, a notorious Russian crime figure.

Finagin's gang is alleged to have committed many contract killings and attempted assassinations in recent years.

Hayrapetyan is to be formally charged in the next few days.