Otago Military History Group chairman Peter Trevathan said his research had led him to believe a siege gun New Zealand forces seized from the Ottoman army during World War 1 was buried under the Oval.
An exploratory dig was conducted to search for the howitzer yesterday in two sections of the Oval, near the Boer War memorial.
The dig failed to reveal the howitzer, but a Masters Games medal from the year 2000 was discovered.
Origin Consultants archaeologist Jeremy Moyle said it was unfortunate nothing was found, but it did not mean the guns were not buried there.
"There’s a lot of Oval — those were two small trenches [we dug]," Mr Moyle said.
The history group had dug about half a metre down until they hit a layer of fill that looked older than what they were looking for and was too shallow to be the major reclamation work that had taken place to create large sections of central Dunedin in the mid to late 1800s.
The dig came after a ground scan of the field conducted by University of Otago geologists Andrew Gorman and Hamish Bowman had revealed between three and four anomalies which Mr Trevathan believed were pieces of the giant gun.
"Back in ’36 they didn’t really care, they dug a hole and rolled it in," Mr Trevathan said.
After World War 1, many reserve units brought artillery pieces back to New Zealand as trophies.
These were gradually removed from public display in the 1930s because of increasing anti-war sentiment.
Mr Trevathan believed the other two field guns had been scrapped, but was optimistic the German-built howitzer, which he believed weighed about 9 tonnes, was still at the field where it had been buried.
He believed the Second Auckland Infantry Battalion seized it in Palestine in 1918.
He hoped a survey using ground penetrating radar could be completed at the Oval before the end of the year.
