A reward for information leading to the arrest of Ruja Ignatova, known as the Missing Cryptoqueen, has been increased by US authorities to $5m (£4m).

The Bulgarian-born German woman, 44, is wanted by the FBI for orchestrating a $4.5bn cryptocurrency scam called OneCoin.

She has been missing since 2017 when US officials signed an arrest warrant and investigators began closing in on her.

Three weeks ago, a BBC podcast and documentary revealed her links to the Bulgarian underworld and the suspected mafia boss involved in her disappearance and, allegedly, her possible murder.

However authorities continue to pursue Ms Ignatova.

In 2022, the FBI added her to its top 10 most wanted list, offering a $100,000 reward, later upped to $250,000.

On Wednesday, that amount increased again twenty-fold, under the US State Department’s Transnational Organised Crime Reward Program.

“We are offering a reward up to $5 million for information leading to the arrest and/or conviction of German national Ruja Ignatova, known as ‘Cryptoqueen,’ for her role in one of the largest global fraud schemes in history,” said US State Department spokesman Matthew Miller.

She is currently the only woman targeted under the US programme.

An equivalent $5m reward is on offer for information about Daniel Kinahan, named as the head of one of Europe’s biggest drug cartels.

The same amount is on offer for information about Semion Mogilevich, alleged to be a Russia-based crime boss, and Yulan Adonay Archaga Carías, known as Porky, the highest-ranking member of the MS-13 criminal gang in Honduras.