A key prosecution witness whose stance triggered charges against a Russian opposition leader has changed the crucial part of his testimony.

The witness, Vyacheslav Opalev, got a suspended sentence in December after pleading guilty to conspiring with Alexei Navalny to steal timber from a state-owned company.

Navalny, who led protests against President Vladimir Putin and exposed alleged corruption in government, is accused of heading a criminal group that embezzled $500,000 worth of timber from that state-owned company while working as an adviser to the Kirov provincial governor in 2009. The charges could send him to prison for 10 years.

But Opalev told the court Thursday that he was forced into a deal by Navalny to buy timber at artificially low prices — rather than colluding with him to steal it.