>"We were not surprised to find another pro-Russian bot network, but we were shocked to learn that some of the accounts in the sleeper agent network have been active for more than a decade," Nina Jankowicz, the group's co-founder and chief executive, told AFP.

>Jankowicz, the former Department of Homeland Security disinformation chief, called on X to take down the network, which has seen an uptick in "abusive and false content" targeting Harris.

Some of the sleepers had managed to avoid detection for as long 15 years.