Oceana's market capitalisation has fallen more than a fifth, or 22.3%, since the potential suspensions were announced. From $4.93, shares were down $1.10c to around $3.83 yesterday.
About half of the country's mines became embroiled in environmental and social allegations a fortnight ago by the Philippines Department of Environment and Natural Resources (DENR), but that department is now also being scrutinised over its last-minute issuing of mining licences, just days before Benigno Aquino stepped down and Rodrigo Duterte began his tenure as president.
Oceana Gold chief executive Mick Wilkes said the Didipio mine was continuing to operate without interruption and he reiterated earlier guidance for production and costs for calendar 2016.
''I'm highly confident that our Didipio operations will continue to operate without interruption, as the Didipio Mine sets the benchmark for responsible mining based on international best practices,'' Mr Wilkes said in an NZX update.
He said Didipio served as the template for the type of operation President Duterte and his administration want for all mining Philippine operations, as they advanced ''a responsible mining sector''.
Almost a fortnight ago, it was reported more than half the operating mines in the Philippines could be suspended, the DENR said, as a mining audit revealed major environmental violations and social development lapses, The Manila Times wrote.
DENR undersecretary Leo Jasareno said that 12 mines, mostly nickel operations in Mindanao, were recommended for suspension, while 18 other companies, including Oceana Gold, were also subject for further review. At the time, Oceana Gold had not been formally approached about any of the issues.
However, late last week The Manila Times reported Environment secretary Gina Lopez had ordered the investigation of alleged ''midnight deals''.
She claimed the deals involved some officials of the DENR (Department of Environment and Natural Resources) and mining companies which were granted an extension, or expansion, of their operations during the last days of the Aquino administration.
Ms Lopez was acting on a complaint from the Alyansa Tigil-Mina organisation, an anti-large scale mining group.
She demanded an audit of all mineral production sharing agreements approved by the Mines and Geosciences Bureau in May and June this year, The Manila Times reported.
