A Russian legal group that recently defended the organisations of Kremlin opponent Alexei Navalny said on Sunday it was disbanding over fears of criminal sanctions.
Team 29 said its website had been blocked after a request from prosecutors, who accuse the group of links with a Czech organisation that has been deemed "undesirable".
Since Navalny's arrest and imprisonment in January, officials have stepped up pressure on critics.
Russian authorities can ban groups declared "undesirable organisations" and members face up to six years in prison.
Saint Petersburg-based Team 29 describes itself as an association of lawyers and journalists fighting for freedom of speech in Russia, where it is known for defending people accused of treason.
The group rejected any link to the Czech organisation and denounced the accusations as "fanciful".
"But we cannot ignore the position of the security forces," the group said in a statement posted on the Telegram messenger.
They feared that "the next step in the attack" would be criminal proceedings against its members and supporters.
"Our lawyers and jurists will continue to work on their clients' cases solely independently," the statement said.
The group said it had deleted all its online archives to avoid any risk.
Team 29 head Ivan Pavlov was arrested in April while he was acting for Navalny and faces accusations of disclosing information about a preliminary investigation.
The courts designated Navalny's organisations as extremist in June, paving the way for a crackdown on his allies.