The lawyer representing the family of Anna Politkovskaya, the murdered Russian journalist, was recovering from an apparent attempt to poison her as the trial opened today of three men accused of involvement in the killing.

A judge in Moscow rejected a request to postpone the preliminary hearing because Karinna Moskalenko was ill in France, where police are investigating the discovery of a large quantity of mercury in her car.

Ms Moskalenko also represents Mikhail Khodorkovsky, the jailed former Yukos founder, who is appealing againts a refusal to release him on parole after serving more than half of an eight-year prison sentence for fraud.

She told The Times that her husband had found large numbers of silvery metal globules under the seat of her car on Sunday, almost exactly two years after Mrs Politkovskaya’s death. She was waiting for the results of police tests to confirm whether she had been poisoned with mercury.

“The machinery of the state is probably now so angry with my activities, but I still don’t know whether we have grounds to link this to my work. I don’t know if it is a demonstrative act to threaten me,” she said from her home in Strasbourg.

“I am quite weak now and have been sick since Friday. I am really angry that I could not come to the Politkovskaya case, I was effectively prevented from coming.” The discovery has prompted speculation that she could have been the target of an attempt to silence her over the case. Exposure to high levels of mercury can damage the brain, heart, kidneys, lungs, immune and nervous systems.

Mrs Politkovskaya was a fierce critic of Vladimir Putin, then the President, and was killed on his birthday in October 2006 by a gunman outside her home. Mr Putin has denied any state involvement in the killing.

Ms Moskalenko specialises in representing cases against Russia before the European Court of Human Rights, where she has won repeated victories for victims of state abuse. She is currently waiting for a key ruling on Mr Khodorkovsky’s imprisonment.

Her success proved so embarrassing for the Russian Government that she became the target of a Kremlin attempt to end her career last year. The Prosecutor-General’s Office sought unsuccessfully to have her disbarred on the extraordinary grounds that she had failed to represent Mr Khodorkovsky properly.

Mr Khodorkovsky’s business empire was dismantled in a Kremlin campaign ordered by Mr Putin. The former oligarch had declared himself “fully satisfied” with his lawyer.

Two Chechen brothers, Dzhabrail and Ibragim Makhmudov, are charged with conducting surveillance on Mrs Politkovskaya and a former police officer, Sergei Khadzhikurbanov, is accused of providing technical help. All three deny guilt.

The man suspected of shooting Mrs Politkovskaya is a third Makhmudov brother, Rustam, who remains on the run. Investigators have failed to identify who ordered the killing.

The trial opened behind closed doors at Moscow’s main military court and was adjourned until November 17 to allow time to form a jury. Lawyers for the defendants and for Mrs Politkovskaya’s family want the trial to be held in public but prosecutors are pressing for a closed court, arguing that the case involves classified documents.

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