MANILA - A ban on open-pit mining has "no legal basis" and is under review, a senior official at the government's mines bureau said on Thursday.

"In the Philippines ... surface mining or 'open-pit' is technically and financially feasible," Larry Heradez, chief of the Mines and Geosciences Bureau's legal division, told reporters.

Heradez is part of a team that is reviewing the policy orders of Gina Lopez, the former environment secretary whose appointment was not approved by lawmakers.

Heradez also said that some of the 75 mining contract cancellations that Lopez ordered may end up being upheld due to "possible violations like non-payment of taxes and non-implementation of work programs".