Wiltshire Council was subjected to massive cyber attacks from abroad shortly after the poisoning of Sergei Skripal, a council boss has said.
Executive director, Alistair Cunningham said the attacks meant staff had to stop wearing Bluetooth devices, such as fitness bracelets, in council meetings. He said: "As soon as we hit the headlines, the number of cyber attacks on our system increased tenfold."
Spy agency GCHQ said 90% of these attacks came from outside Britain.
Police under attack
GCHQ also said the attacks were "well-coordinated".
Mr Cunningham said: "They were attempts to break through our firewall, go to the internal network, pick up passwords to employees' email. "In the hottest days, we received 90,000 attacks a day." He made the comments after a parliamentary meeting on Tuesday.
The IT systems of Wiltshire Police also came under attack because they use the computer resources of the local administration, he said.
The first attacks on the the council network was so strong it had to urgently ask for help from GCHQ.
"We were told to hold meetings in a sterile setting.
"That is, essentially, the old fashioned way - without mobile phones and other high-tech pieces.
"We were asked to remove and lock various devices working via Bluetooth; for example pedometers and fitness bracelets," said Mr Cunningham.Access to these resources through personal tablets and phones was also denied.
According to GCHQ, cyber attacks could have two goals: either to significantly slow down the work of local authorities, or to covertly penetrate domestic resources, especially police information.
British cyber security experts said most of the attacks occurred in the first five months after the poisoning of Sergei Skripal.
The double agent, and his daughter Julia, were poisoned in March 2018.
Later, three others were also poisoned and Dawn Sturgess died.
The Russian authorities have consistently denied allegations it wanted to assassinate the former spy.