A SUSPECTED member of a Chechen gang was arrested in Moscow while carrying nearly 18lb of mercury, and authorities believe he intended to use the poison in a terror attack, police said yesterday.

Facing growing criticism of the secrecy surrounding how the Moscow theatre siege was ended, Russian officials today showed off explosives and other evidence found at the scene.

RUSSIA said yesterday the gas used in its disastrous Moscow theatre raid was based on Fentanyl, a fast-acting opiate with many medical applications.

Russia’s top health official today revealed that the gas used in the special forces storming of a Moscow theatre held by dozens of gunmen was based on Fentanyl, a fast-acting opiate that has many medical applications.

Two more hostages, freed from the Moscow theatre siege by Russian troops, died in hospital overnight from the gas used to incapacitate them and their captors.