Trade minister Akihiro Ohata said Friday the ministry has received some reports confirming imports of rare earths from China have been halted, saying Japan may file a complaint with the World Trade Organization if it is a retaliatory move by Beijing over the detention of a Chinese trawler captain.

"We have only received fragments of information (from trading companies), and we're trying to understand the overall situation," Ohata told a news conference in the morning at the Ministry of Economy, Trade and Industry.

If the government finds Beijing is delaying the process intentionally, "we would take appropriate action according to (WTO) rules," Ohata said.