Problems with the police radio system in the minutes before Jean Charles de Menezes was shot dead were high-lighted at the inquest yesterday.

One of the two marksmen who fired the fatal shots said that reception on his Cougar radio was “awful” on the morning of the incident. The firearms officer, codenamed C12, tried to listen in on communication between the surveillance officers following Mr de Menezes as he approached Stockwell Tube station, but the signal was so bad that he suspected it was suffering from interference from other police units.

“They were so bad that I distinctly remember thinking that another channel is coming over into our channel,” C12 told the inquest.

Sir Michael Wright, the coroner, asked him whether he meant that the radio signal was weak, faint or fuzzy so he could not understand what was being said. The firearms officer replied: “All of those – it was awful.”

The quality of the signal improved as C12 approached Stockwell, but it was suggested in the hearing that he may have missed important messages about the operation.

C12 said that problems with the Cougar system were well known. “They are old technology and they could be affected by weather, height of buildings, distance you are from other transmitters,” he said. He was asked if there were times when the radios would cut out altogether. He replied: “Yes, that is quite possible. The battery life on them was notoriously bad.”

Tens of millions of pounds have been spent on the Met’s radio system and it is now considered to be substantially better than it was in 2005.

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