Questions have been raised as to the role and functions of Sarawak's state oil and gas company Petros, after national firm Petronas awarded a gas field off the coast of Miri to a Japanese group.

Kelvin Yii, an aide to Sarawak DAP chief Chong Chieng Jen, said Petronas' move was an exploitation of the state's resources.

"The rights of oil and gas has been given to a foreign company over our resources, rather than the said state-owned Petros that was said to propel us into the position to harness our own resources," Yii said in a statement.

Yii wants Sarawak Chief Minister Abang Johari Openg - who set up Petros - to explain whether the state government was consulted on the move and it the state exerted its rights.

He also wants to know how the state would benefit from this, and if the state is only getting a 5 percent oil royalty.

The Borneo Post reported yesterday that Japan's JX Nippon Oil and Gas Exploration won the rights to mine the Beryl gas field off the coast of Miri.

Petronas reportedly approved JX Nippon's field development plan for Beryl on Oct 27.

Petros was officially formed in August to enable Sarawak to actively participate in the extraction of oil and gas in Sarawak.

The company was formed as an additional means to secure oil revenue for the state, on top of demands for its oil royalties to be increased to 20 percent.