NO return address, no handwriting and probably no fingerprints were to be found on letters containing Mayor Margaret Strelow's closely guarded work mobile number which were leaked to the public.
Despite yesterday fielding many more calls than usual on what she calls her "bat phone", Cr Strelow was unfazed by the mysterious leak.
And she refuses to change the number.
The list of potential "suspects" remains quite slim, with her husband, council CEO Evan Pardon, councillors, those in her private circle and other emergency numbers, such as The Morning Bulletin, given the number by Cr Strelow.
But she said there would be no investigation into the identity of the culprit.
"I'm not bothered," she said.
"If it was a bunch of confidential council documents I would be.
"But it doesn't really matter.
"It's my bat phone - for when I'm needed in meetings and things."
Cr Strelow said she undestands former Rockhampton Regional Council Mayor Brad Carter made his mobile phone number public when he was in office.
But tech-savvy Cr Strelow said she chose to be more available to the public in a different way.
"People run their lives differently," she said.
"I'm trying to be as accessible as possible, with Twitter and Facebook.
"Or people can ring the office.
"My home number is now listed.
"I understand there will always be someone who wants more one-on-one contact."
While the total number of people who received the letters is unknown, local businessman Petros Khalesirad said he along with at least five other people received them.
"I think it was weird," Mr Khalesirad.
"It was to demonstrate to people at the table that there are people who are going to leak things."