Influential Ukrainian tycoon Dmytro Firtash is among eight people targeted by fresh British sanctions that accuse the group, which includes his wife, Lada, of large-scale, international corruption.
Angolan-Russian billionaire Isabel dos Santos and Latvian politician and businessman Aivars Lembergs are also among those hit by the new sanctions announced on November 21.
The British government accuses Firtash of bribing officials to secure mining licenses for his companies and profiting illegally from Ukraine's gas-transportation system.
Firtash is also linked to financier Denys Horbunenko, a resident of the United Kingdom who was added to the sanctions list on November 21 for his association with Firtash.
Firtash has faced legal scrutiny in Ukraine over embezzlement and money-laundering accusations involving fraudulent gas-trading schemes.
The United States has been seeking his extradition from Austria on charges of bribing Indian officials.
SEE ALSO: Whither The Oligarchs? Amid Russia Crisis, Fears For Ukraine's Struggle To Uproot CorruptionFirtash, who gained prominence in the 2000s through his joint venture RosUkrEnergo with Russian energy giant Gazprom, has denied allegations of working in Russia's interests.
Dos Santos, daughter of former Angolan President Jose Eduardo dos Santos, is Africa's first female billionaire. She is accused of corruption in Angola, where she allegedly exploited her political connections for personal gain.
Dos Santos claims she has held Russian citizenship since birth, as she was born in Baku, Azerbaijan, in 1973 under the former Soviet Union.
Lembergs, a former populist mayor of the Latvian city of Ventspils, has been convicted in Latvia of corruption and sentenced to five years in prison. He claims the charges against him are politically motivated.
The sanctions are part of a British efforts to combat international corruption and disrupt the financial networks of individuals accused of abusing their power for personal enrichment.
The measures include asset freezes, travel bans, and restricting these individuals from accessing the U.K.'s financial system or entering the country.