Alexander Litvinenko, an intelligence agent turned Kremlin critic, died in London in 2006 after drinking tea laced with the radioactive isotope polonium-210.
Britain has accused two Russians of the killing, but Moscow has refused to extradite them.
Coroner Robert Owen had decided to reveal some material, arguing that the disclosure was necessary for a "fair and meaningful" inquest into Litvinenko's death.
Today, Foreign Secretary William Hague succeeded in overturning Owen's decision to disclose some documents.
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Goldring noted in his decision that the case concerned the risk of "significant damage" to national security.
"Nothing we have decided reduces the importance of open justice," he added.
Litvinenko's widow, Marina, said through her lawyer that she was "disappointed but not surprised" by today's ruling.