There is no evidence of any abuse of process in the trial of Mikhail Khodorkovsky, once Russia's richest man and his business partner Platon Lebedev, Investigative Committee spokesman Vladimir Markin said on Tuesday.
His comments came after Natalya Vasilyeva, a former court aide, was questioned earlier in the day at the request of Khodorkovsky's defense team.
Khodorkovsky and Lebedev have been in prison since 2003 and were convicted on a second set of charges in December, extending their term to 2016.
In February, Vasilyeva said that the verdict on Khodorkovsky was imposed on Judge Viktor Danilkin by his superiors at the Moscow City Court. Danilkin denied the accusation.
Markin said Vasilyeva's allegations were "only based on assumptions and guesswork and not substantiated by any objective facts."
Khodorkovsky and Lebedev have always maintained that the charges against them have been trumped up.
The Russian government has always denied there was any political motive for Khodorkovsky's prosecution and has defended the validity of the legal process in the affair.