A Chinese coast guard ship has been accused of "forcefully retrieving" a floating object, believed to be rocket debris, from a Philippine vessel in the South China Sea.
Vice Admiral Alberto Carlos of the Philippine Navy said a Chinese vessel blocked their course twice, before finally seizing the object.
Chinese officials have yet to respond to the allegations.
It comes as US Vice President Kamala Harris visits the Philippines.
The debris was first spotted on Sunday at 06:45 local time (22:45 GMT Saturday), near the Philippine-controlled Pagasa Island, also known as Thitu Island, said Vice Adm Carlos.
He added that officers proceeded to the site and found a "metallic" unidentified floating object.
As they were towing the object back, a Chinese coast guard vessel with the bow number 5203 approached their location and "subsequently blocked their pre-plotted course twice".
He said the Chinese boat then "forcefully retrieved" the object by cutting the towing line attached to the Philippines' rubber boat. No one was injured in the incident, he added.
Spokesperson Cheryl Tindog said the sailors did not fight the seizure since it was "not a matter of life and death".
The Philippines' Department of Foreign Affairs said they were aware of the incident and a review would be conducted.
Earlier this month, metal debris was similarly found off Busuanga island in western Palawan and in Calintaan town in Occidental Mindoro province.
Officials had said they believed the pieces were likely to be parts of China's Long March 5B rocket, which blasted off earlier in November from the Wenchang Space Launch Centre on Hainan island.
Hainan island is slightly more than 1,000km (621 miles) away from where the latest object was found.
China has previously been criticising for allowing rocket stages to fall back to Earth.
US space agency Nasa has in the past called on China to design rockets to disintegrate into smaller pieces upon re-entry, as is the international norm.
The incident comes as the US Vice President is due to visit the Filipino island of Palawan, which lies along the hotly contested waters of the South China Sea.
Ms Harris is the highest-ranking US official to visit since President Ferdinand Marcos Jr took power, and the visit is likely aimed at reviving ties with Manila.
"We stand with you in defence of international rules and norms as it relates to the South China Sea," Ms Harris told Mr Marcos at the start of talks.
The South China Sea is one of the most disputed regions in the world - with several countries claiming ownership of its small islands and reefs and with it, access to resources.
In recent years, China has been increasingly assertive over what it claims are its centuries-old claims to the contested region, and has been rapidly building up its military presence to back up those claims.
Brunei, Malaysia, the Philippines, Taiwan and Vietnam contest China's claim to almost all of the South China Sea.