Valiantsin Stefanovic is a member of the Viasna Board and the vice-president of the International Federation for Human Rights (FIDH). He is a well-known human rights expert and analyst advocating non-discrimination and abolition of death penalty. He participated in various international conferences, meetings, human rights missions, and election monitoring missions in the OSCE countries.

The law enforcers came to his apartment in the morning of July 14, 2021. They seized all the offcie equipment. Valiantsin Stefanovic was taken for interrogation.

The search was carried out by officers of the Financial Investigations Department. The search warrant listed two articles of the Criminal Code: Part 1 and 2 of Article 342 ('Organizing and participating in actions grossly breaching public order') and Part 2 of Article 243 ('Tax evasion').

On September 26, 2022, it became known that the criminal charges of ‘tax evasion’ under Part 2 of Article 243 of the Criminal Code against Valiantsin Stefanovic, Ales Bialiatski, Uladzimir Labkovich, and other Viasna members were dropped. However, Bialiatski, Labkovich, and Stefanovic were not released from custody as they were charged with ‘smuggling’ by "having illegally been moving cash across the customs border of the Eurasian Economic Union in large amounts by an organized group” under Part 4 of Article 228, and with ‘financing of group activities, grossly breaching public order’ under Part 2 of Article 342 of the Criminal Code. It is known that the state's claims refer to the same amount of money, which appeared in the charges of tax evasion. The three political prisoners faced from 7 to 12 years in prison.

On October 27, 2022, at the 41st Congress of the International Federation for Human Rights (FIDH), Valiantsin Stefanovic was re-elected the Vice President of FIDH.

On November 28, 2022, the General Prosecutor's Office sent the Viasna case to the court. The trial began on January 5, 2023 in the Lieninski District Court of Minsk. The case was considered by Judge Maryna Zapasnik, with Aliaksandr Karol as the prosecutor. Ales Bialiatski, Valiantsin Stefanovic, and Uladzimir Labkovich did not plead guilty to any of the criminal charges.

On March 3, 2023, in the Lieninski District Court of Minsk, Judge Marina Zapasnik sentenced:

• Ales Bialiatski, the chairman of Viasna and Nobel laureate, to 10 years of imprisonment in a medium-security penal colony
• Valiantsin Stefanovic, the deputy chairman of Viasna and the vice-president of FIDH, to 9 years of imprisonment in a medium-security penal colony
• Uladzimir Labkovich, a lawyer and the coordinator of the Human Rights Defenders for Free Elections campaign, to 7 years of imprisonment in a medium-security penal colony
• Zmitser Salauyou, a human rights defender of Viasna, to 8 years of imprisonment (in absentia).

The sentence is two years shorter than that requested by the prosecutor Aliaksandr Karol. All of the defendants, except Ales Bialiatski, were also fined BYN 111,000 (approx. USD 38,950). The chairman of Viasna Ales Bialiatski was fined, as requested by the prosecutor, BYN 185,000 (approx. USD 64,912). Besides, it was decided to jointly and severally collect from Bialiatski, Stefanovic, Labkovich, and Salauyou the amount of BYN 752,438 (approx. USD 297,650), which they allegedly "obtained by criminal means" through "smuggling by an organized criminal group". That was the very amount that had appeared in the charge under Part 4 of Art. 228 of the Criminal Code.

Their colleagues, other human rights defenders, the international community and ordinary Belarusians have reacted harshly to the sentence. The UN issued a statement on this occasion.

Prosecutor Aliaksandr Karol filed an appeal against the sentence: he had demanded two-year longer prison sentences and larger fines, but Judge Maryna Zapasnik passed a different sentence.

On April 21, 2023, in the Minsk City Court, Judge Sviatlana Bandarenka considered the appeals against the verdict filed by the political prisoners and their defenders. She uphold the sentence and dismissed their appeals.

On May 2, 2023, it became known that the human rights defender was transferred from remand prison #1 in Minsk to penal colony #15 in Mahilioŭ.

In July 2023, Valiantsin Stefanovic called his wife for the first time in two years.

“Criminal prosecution of Viasna members is not related to their work,” authorities responded to the UN request

The website of the Office of the UN High Commissioner for Human Rights has published the official response of the Belarusian government to the request of four Special Rapporteurs on the search and detention of human rights defenders, NGO representatives, and independent media, which took place in July 2021.