The original email was forwarded to another councillor at the time and no-one else, Calvert said.
"I do not know whether it is just personal against me and or politically motivated because over the past month there has been a range of other petty information being leaked involving myself and others.
"I am deeply suspicious that they were also Justin, and that his email to me was actually intended for the media. If so, such information leaks may well be more than trying to harass me and at worst could be trying to undermine this Council as a whole, either by just himself and or with others."
When asked for comment Lester said he had little interest in having a public or private "spat" with Calvert.
He said the email was a heads up to Calvert he had received an inquiry about ratepayer funded mileage for councillors, which he was strongly opposed to.
"I have always treated all councillors with dignity and respect, he said.
Calvert has asked for an investigation into how Lester came to be in possession of an email she did not provide to him, and who he was sending it to when he "apparently accidentally" sent it to her.
The chief executive's office declined to comment. The mayor's office has been approached for comment.
