The Philippines said Tuesday it would destroy five tonnes of confiscated elephant tusks as part of a global campaign to raise awareness against the illegal trade of so-called "blood ivories".

The seized tusks represent a portion of the 13.1 tonnes of Tanzanian elephant tusks seized in 2005 and 2009 that are kept in a government vault, said Protected Areas and Wildlife Bureau head Theresa Mundita Lim.

"This action is meant to send a message that the Philippines is against the illegal trade of ivory and the merciless massacre of elephants," Lim told AFP.

She said the haul will be crushed using a road roller and burned in front of anti-ivory trade advocates next week as the country works to shed its image as a major transport hub for illegal ivories.

The rest of the seized ivory will remain under lock and key and will be used as evidence against illegal traders or as educational materials.

The Philippines is a signatory to the Geneva-based Convention on International Trade in Endangered Species of Flora and Fauna (CITES), which bans the trade of ivory in a bid to combat drastic declines in the numbers of elephant populations in Africa.

It cited the Philippines as among nine countries considered as "priority concerns" because they were used as a smuggling hub for illegal ivories, Lim said.

The maximum penalty for possessing illegal ivory in the Philippines is four years in jail.

Authorities last year launched an investigation into religious icons made from ivory that were owned by the influential Catholic church.

The inquiry was sparked by a National Geographic magazine report that quoted a prominent priest who gave a list of known ivory carvers in Manila and offered tips on how to smuggle the icons abroad.

The church had denied it condoned the massacre of elephants, saying many ivory statues it owned were decades old and made even before the ban on ivory trade came into force.

But Lim said the investigation continues, even as she declined to give further details citing the inquiry's sensitive nature.

The church remains highly influential in the mainly Catholic country of 100 million.