Philippine court and diplomatic officials say a pre-trial hearing for nine Chinese fishermen accused of poaching sea turtles in a disputed South China Sea shoal in a case likely to further strains relations with Beijing has been postponed again because of problems finding a qualified interpreter.

The Chinese were arrested in May and authorities seized their boat that was allegedly filled with giant turtles at the Half Moon Shoal in the disputed Spratly Islands. The arrests sparked another territorial spat between the Asian neighbors in the increasingly volatile South China Sea.

The fishermen have pleaded not guilty to charges of violating two provisions of the Philippine fisheries code, including illegally harvesting 555 endangered turtles, before a special environmental court in western Palawan province, which lies closest to Half Moon Shoal.