The Supreme People's Procuratorate and the Ministry of Public Security said on Monday that they have dispatched a joint team to Shandong province to supervise the investigation of a case in which a former company executive was suspected of sexually assaulting his "adopted" teenage daughter.

The case triggered wide attention nationwide last week after Chinese media reported a woman's allegation that her "adopted "father, surnamed Bao, had started sexually assaulting her around 2016 when she was 14 years old.

The woman also said she had sought help and had been trying to get Shandong police to take action since last year, but the case was withdrawn after it was first filed in April 2019, according to a report by South Reviews, a Guangdong-based magazine, on Sunday.

But Bao, who served as a vice-president in charge of legal affairs of Yantai-based Jereh Oilfield Services Group and an independent nonexecutive director of ZTE Corporation, denied the adoption and told the magazine the woman falsified the facts.

On Thursday, the Zhifu branch of the Yantai public security bureau in Shandong, posted a statement on its Weibo account that they received a woman's report on April 8, 2019, in which, she claimed she had been sexually abused several times by Bao over the past three years.

"We filed the case the next day and asked prosecutors to help investigate," the police said in the statement. "But after the investigation, we didn't think the evidence was enough to prove Bao committed a crime, so we withdrew the case on April 26 last year."

The branch reopened the case on Oct 9 last year after the woman and her lawyer provided new clues, it said, adding the investigation is still ongoing and evidence is being collected.

Jereh Oilfield Service Group said it terminated Bao's contract last Thursday, and he resigned from ZTE Corporation, ZTE said in a statement on Friday.

On Saturday, the public security bureau in Yantai also said in a statement that it has established a special work team to conduct a thorough inspection on how the Zhifu branch dealt with the case in its early stages.

According to public information and ZTE's 2018 annual report, Bao, who was born in 1972, worked as a lawyer, partner and senior legal adviser in Beijing and Tianjin, and also in New York and California for a couple of years.