The Chinese mainland accused Taiwan of harming cross-Straits relations by playing up a case involving a Taiwan man who is under investigation on the mainland, an official said on Wednesday.

Lee Ming-che, a Taiwan resident, was detained on suspicion of harming national security this month.

An Fengshan, a spokesman for the State Council Taiwan Affairs Office, reiterated at a regular news conference on Wednesday that Lee is being investigated in accordance with the law for suspected activities endangering national security.

The communication mechanism across the Taiwan Straits has been suspended since last year because the island's new leader, Tsai Ing-wen, has failed to acknowledge the 1992 Consensus, which embodies the one-China principle.

Considering human rights, the mainland-based Association for Relations Across the Taiwan Straits has entrusted a Taiwan-based NGO to inform Lee's wife of the case and pass letters from him to his family, An said.

Families can also pass on related goods to Lee, he said, adding that so far, the association has not yet received any goods from the family.

"Some groups in Taiwan with ulterior motives have used the case to attack the mainland, cause trouble and interfere with the investigation. They won't succeed," An said.

Lee was reported missing on March 19, while in Guangdong province. According to media reports, Lee had planned to attend a meeting that day in Zhuhai, but failed to show up.

An also welcomed Taiwan businesses to join the Xiongan New Area development.

"All businesses, regardless of their country, region or city, are welcome to join the Xiongan New Area program, as long as their line of work suits the overall industrial plan of the area," An said.

On April 1, the Communist Party of China Central Committee and the State Council announced the establishment of the new area to boost the coordinated development of Beijing, Tianjin and Hebei province.

luowangshu@chinadaily.com.cn