NHK has learned that a large piece of metal believed to be Chinese rocket debris has been washed ashore on an island in southwestern Japan.

A resident of Okinoerabujima Island in Kagoshima Prefecture found the white object on April 20.

The piece is about 3 meters long and 2 meters wide. On its surface is painted what looks like part of the Chinese national flag, with yellow stars on a red background.

It also carries Chinese characters meaning "exhaust vent."

Tsujino Teruhisa, who used to work for Japan's space agency JAXA, has seen images of the object. He is an expert on China's space development.

Tsujino says judging from its shape and other features, it is highly likely the debris is part of the payload cover of a Chinese Long March rocket. The cover, or fairing, is designed to protect satellites and other payloads.

The Wadomari town office on the island says no damage has been confirmed so far. Town officials say they have consulted the prefectural government for advice.

China said on April 16 that it had successfully launched a rocket carrying a weather satellite.

The country had set up a no-fly zone over waters north of Taiwan on the morning of that day for what it called space activities, and banned the navigation of vessels in the area for six hours.