A statue commemorating a Japanese civil engineer in southern Taiwan who contributed to Taiwan’s development was found decapitated Sunday, local media reported.

Central News Agency and other outlets said an investigation is underway to uncover the motive behind the vandalism and that Tainan Mayor William Lai has instructed local police to form a special task force to look into the case.

CNA reported that local police received a tip Sunday morning that the bronze statue of Yoichi Hatta at the memorial park in Guantian, Tainan City, had been defaced.

The vandalism incident happened only three weeks before an annual memorial service is to be held at the park. The head has yet to be recovered.

The park was commissioned in 2011 to honor Hatta’s contributions to Taiwan. The statue depicts Hatta sitting on the ground, extending one foot forward and supporting his head with his right hand.

Hatta was stationed in Taiwan from 1910 until 1942, during which time he built the Chianan Canal and Wushantou Reservoir in the island’s southwestern Chianan Plain as key components in a massive irrigation system, one of many infrastructure projects Japan implemented to modernize Taiwan during its 50-year occupation that ended in 1945.

Thanks largely to Hatta, the Chianan Plain, once an arid wasteland with soil in the coastal area contaminated by high levels of salt, has become one of the most productive agricultural regions in Asia, growing a wide range of food crops, including over 60 percent of Taiwan’s rice.

Hatta was killed in an Allied submarine attack on a ship transporting him to the Philippines in 1942. Distraught by his death, Hatta’s wife jumped to her death from atop the reservoir he built that would bring prosperity to the once-poor area.