"The first I knew of them was my mum drove past one outside Te Puna Hall and told me," he said.
The other signs are understood to be in Bethlehem, at Te Puna Rugby Club and at the Tauriko and Cambridge Rd intersection.
Thwaites has remained steadfast in his promise not to spend any money on the election. He has gone as far as to proclaim himself as the future "cheapest mayor in New Zealand".
Asked if he had any concerns the signs would impinge on his efforts to appear thrifty, Thwaites said no.
However, he said he could become so. "I am concerned if there are more than four signs."
It is understood there are six.
Tommy Wilson, who has strong Te Puna roots, said he believed the use of blue and black represented the local rugby club. This was especially so because the Te Puna rugby players were known for standing to salute after scoring a try.
Wilson would not confirm whether he was responsible for the signs but said "if it was me, the reason I would be doing this is to encourage people to vote".
"Don never asked me to do it."
Wilson said he was hopeful for these elections, in which existing Western Bay mayor Garry Webber will step down and a new mayor will be elected.
"If we can get a mayor as good as the outgoing mayor, we are in good stead. We've been really well serviced by Garry. He engaged with every sector of the community."
Others also running for the mayoralty are Suaree Borell, Mark Boyle, James Denyer, Paul Haimona, Rodney Joyce, Terry (Hori Bop) Leaming, and John Scrimgeour.
Special voting begins in this year's election begins today and the election day is on October 8, with final results declared from October 14.
More information about the Western Bay candidates and election can be found at the Generation Change website.
