PANAMA CITY (AP) — Panamanian investigators carried documents Thursday out of offices belonging to a Hong Kong-owned company that operated ports at either end of the Panama Canal until its concession was declared unconstitutional by the Supreme Court last month.

Public prosecutor Azael Samaniego, of the anti-corruption office, told local media outlets that visits were made to three offices of the Panama Ports Company in Panama City and that the Panama Maritime Authority and investigators from the National Directorate of Judicial Investigation also participated. The Panama Ports Company is the local subsidiary of Hong Kong-based CK Hutchison.

Samaniego said his office had information pointing to the possible commission of a crime, but he did not specify what the crime could be. He said an investigation was in its early stages.

The Panama Ports Company did not respond to requests for comment, nor did Panamanian law enforcement agencies.

The investigation comes days after the Maritime Authority seized the Balboa and Cristobal ports from the Panama Ports Company. The company has previously rejected the court’s ruling and the Chinese government has accused Panama’s government of bowing to United States pressure.

The ports, which have been operated by the company since 1997, became embroiled in a legal dispute after getting caught in the middle of the U.S. and China’s competition for influence in the region.

The Trump administration objected to the ports being controlled by a Chinese company and accused China of running the canal, something both Panama and China deny.