Seventy-seven Chinese, including 45 Taiwan residents, have been repatriated from Africa and are being investigated for suspected telecommunication fraud, the Taiwan Affairs Office of the State Council said on April 13.

An Fengshan, the office’s spokesman, said at a regular news briefing that in recent years, wire fraud criminals from Taiwan have obtained more than 10 billion yuan ($1.5 billion) yearly from the Chinese mainland. Only 200,000 yuan has been recovered, he said.

“The case is considered China’s first large-scale repatriation from Africa of telecom fraud suspects,” said a senior official of the Ministry of Public Security who requested anonymity.

On April 13, police in Kenya transferred 67 of the suspects to Chinese authorities. They arrived on chartered flights at airports in Beijing and Jiangsu, Hunan and Sichuan provinces.

The 10 other suspects, including eight from Taiwan, were repatriated to the mainland on April 9 to stand trial.

The case dates to November 2014, when police in Kenya discovered tools used by the criminals, including computer data interchangers, in a house in the capital, Nairobi. Through further investigation, the Kenyan police uncovered a cross-border telecom fraud ring. They detained 48 suspects from the Chinese mainland and 28 from Taiwan.

According to the ministry, the criminal gang established many fraud dens in Nairobi and recruited phone callers to pose as law enforcement officers from the Chinese mainland to swindle Chinese residents in nine areas, including Beijing, Jiangsu and Sichuan.

“The victims, including elderly people, migrant workers, laid-off workers and students, were cheated out of a large amount of money by the swindlers. Many families and enterprises became bankrupt, and some of the victims have committed suicide,” the official said.

“Our judicial department will investigate the Taiwan suspects according to law, and their legal interests will be protected,” said An, the office spokesman.

According to the ministry, police officers will update the Taiwan side on developments after careful investigation. Additionally, Taiwan judicial authorities will be invited to the Chinese mainland for discussions on combating cross-Straits telecom fraud.

Since an agreement was signed on both sides of the Straits in 2009 for a joint effort to fight crime and for mutual legal assistance, severe measures have been taken to crack down on wire fraud involving Taiwan residents, the ministry said.

The two sides have launched 47 joint law enforcement operations in Southeast Asia and destroyed more than 500 dens, cracking about 10,000 wire fraud cases. More than 7,700 wire fraud suspects, of whom 4,600 are from Taiwan, have been arrested, according to the ministry. When Taiwan suspects were handled by the island, many were not punished, and money obtained through fraud was not paid back to victims on the mainland, it added.

Zhang Zhijun, head of the Taiwan Affairs Office, talked with Andrew Hsia, Taiwan’s mainland affairs chief, via a hotline on April 12, discussing the repatriation and investigation of the Taiwan suspects.

Zhang said telecommunication fraud allegedly conducted by the Taiwan suspects and involving mainland residents occurred despite repeated prohibitions. Criminals must be brought to justice to protect people’s interests, he added.