Finland on Wednesday charged a hacker, accused of the theft of tens of thousands of records from psychotherapy patients, with over 21,000 counts of extortion, the national prosecutor announced.

"The suspect is held on remand and has denied being guilty of the offences," the National Prosecution Authority said in a statement.

The prosecutor is seeking a seven-year prison sentence for the defendant, Aleksanteri Kivimaki, who was formerly identified as Julius Kivimaki.

In the 2018 breach of the Finnish firm Vastaamo, which oversaw dozens of psychotherapy centres throughout the Nordic nation, the private treatment records of tens of thousands of patients were stolen.

After stealing the records, Kivimaki initially sought to extort over 360,000 euros ($381,000) in bitcoin Vastaamo in exchange for not leaking the records, according to the prosecutor.

When Vastaamo refused to pay, Kivimaki started leaking the records as a means of putting pressure on the company.

According to the prosecution, Kivimaki also sent extortion letters to patients demanding sums ranging from 200 to 500 euros to prevent the disclosure of records of their therapy sessions.

Kivimaki was also charged with 9,598 counts of dissemination of information infringing on personal privacy.

Following a European arrest warrant issued by the Finnish police in October 2022, he was arrested in the Paris region on February 3.

Kivimaki has previously been convicted on various charges of cybercrime, fraud, and money laundering, as well as 50,700 data breaches carried out in conjunction with a hacker group in over a hundred countries.

The trial is scheduled to begin on November 13 and is expected to last until February of next year.

(AFP)

Aleksanteri Kivimäki at the District Court of Western Uusimaa in February 2023. (File Photo)

Finland charges psychotherapy hacker with extortion