Former shock jock Michael Laws - once an MP and mayor of Wanganui - is thought to be considering a rerun for his old mayoral job.
A source told the Herald on Sunday Laws has been sending more emails recently about civic affairs.
Laws was weighing up the position, but would not announce he was standing until the last minute, the source said.
"It certainly wouldn't surprise me."
Current mayor Annette Main, whose husband John Blythe died this week, said she would stand again and was not concerned by talk of a challenge.
Laws told the Herald on Sunday: "I haven't given any thought to local body elections whatsoever."
Meanwhile, the Serious Fraud Office said this week it was investigating the Taupo District Council. Mayor Rick Cooper has already said he is standing down after two terms.
It was time to encourage youth to have their turn, Cooper said.
Deputy mayor Mike Downard confirmed he had eyes on the mayoral chains.
In Auckland, Mayor Len Brown's main challenger remains millionaire John Palino, and in Wellington, Mayor Celia Wade-Brown will face longtime councillor and former Kiwi cricketer John Morrison.
Conservative Party leader Colin Craig said he had turned down more than 100 requests to run in Auckland.
"We are looking to the national election," he said.
In Hamilton, Julie Hardaker has yet to have a confirmed opponent.
In Rotorua, former MP Steve Chadwick and Rob Kent will try to topple Kevin Winters.
In Whangarei, Morris Cutforth is stepping down and predecessor Stan Semenoff will step up with six other hopefuls.
Far North mayor Wayne Brown would not discuss his intentions, but former cabinet minister John Carter has said he wants the job.
The country's toughest battle could be between incumbent Bob Parker and Labour MP Lianne Dalziel, in Christchurch.
Nominations open on July 26 and elections will be on October 12.