The former mayor of Aylesbury and the current chairman of the independent advisory group at Thames Valley Police, said he was amazed and astonished she has been implicated in Westgate shopping centre terror attacks.
Niknam Hussain said it was "just amazing" to speculate that a housewife from "leafy Buckinghimshire" has been transformed into a "mastermind or kingpin" of terrorism.
"I'm astonished and amazed. I can't believe it's true in any which way. Until they provide us with proof, I think it's innocent until proven guilty, to be honest.
"She went to one of the local secondary schools. I've spoken to teachers of hers - nothing untoward or amazing about her.
"When you think you're trying to ascribe a level of sophistication and intrigue to this person that she can ghost herself away, and her children, to become the kingpin. I'm just amazed."
Mr Hussain also knew Lewthwaite's husband, and described him as seeming "perfectly normal" when he met him a few weeks before took part in the July 7 bomb.