Similarly, a Whanganui District Council spokesperson said the council was unaware of who put the bikes there.
Ritani did say that the bikes were discussed at a recent visit to the South Mole by the Te Pūwaha project, a project already under way with the intention of revitalising Whanganui's port.
The intention of the project is to ensure that Whanganui's port is a long-term community, economic and recreation asset, according to Horizons.
Currently strengthening work is underway to repair the north mole as part of the project, with the plan to eventually make the same repairs to the south mole.
Gavin Brooks, a member of Te Mata Pūau, said that while the bikes have been mentioned in passing, Te Pūwaha members have not yet considered whether the bikes will be removed as part of the repairs.
However, Ritani said they are currently sourcing input from the community, and would be interested to hear what people think about them.
"If the community are keen to incorporate them into the proposed South Mole works scheduled for later this year, we would look to do so," Ritani said.
Opinions on the bikes from the community seem mixed.
"It's probably being done by someone who has too much time on their hands," said one of the Te Pūwaha workers on the North Mole.