And the president of the society looking after it says it may not be ''politically correct'' to display the captured World War 1 weapon in the area popular with tourists.
Otago Peninsula Museum and Historical Society president Warren Morris said while the gun was restored in 2007 because of rust and rotten wooden wheels, history had repeated itself.
The replacement wheels had started rotting again and the gun itself was rusting, so the society had shifted it into storage at the Otago Peninsula Museum.
''It's in a bit of a holding pattern really,'' Mr Morris said.
The 75mm Krupp field gun was put back in place in 2007 after an absence of almost three decades. It was understood the gun was originally placed at a small roadside rock outcrop across from Portobello's Coronation Hall in the early 1920s.
Mr Morris said having a steel gun with wooden wheels so close to seawater meant exposure to salt spray. Wood used for the restoration appeared to be untreated.
About six months ago the gun was removed from the site, he said, and ''we don't know whether it's a good idea to actually put it back.''
Portobello Rd would soon be widened, so it was unknown if the space would still be available.
Mr Morris also wondered how politically correct it was to have the gun on public display.
''It wasn't there as a defence. It was put there as a trophy gun.
''It wasn't as if it was part of our coastal defences.''
He said there was space to display it at the museum if necessary, but it was up to the society to decide.
