Police have arrested a divorced man and his mistress for subjecting his ex-wife to months of illegal surveillance, intimidation and extortion to gain control of half of her company, local media reported Friday.

The suspects, surnamed Zhu and Liu, spent almost a year spying on their victim, surnamed Wei, by installing monitoring software on her computers and bugging her home, her car and her luggage in a plot to destroy her reputation, according to a report in the Xinmin Evening News. By the time they were caught, the pair had cost Wei's company more than 100 million yuan ($16.5 million) in lost business.

Police said more and more illegal surveillance cases have emerged as technology has advanced, according to the report. Last year, Shanghai police arrested about 190 suspects for the illegal trade or use of surveillance equipment, seizing 500 pieces of equipment and more than 100 million pieces of personal information.

Zhu and Wei ended their 17-year marriage in 2012 after it came to light that Zhu had been having an affair with Liu for the previous eight years.

In May 2012, a court deemed Zhu responsible for the failure of their marriage and awarded Wei complete ownership of the company in the divorce settlement. The court left Zhu with several apartments and an undisclosed amount of money.

Unsatisfied with the ruling, Zhu began to monitor Wei in November 2012, presumably so he could uncover information that he could use to blackmail her into turning over ownership of half of the company.

Wei first got an idea of Zhu's plans on April 7, 2013, when someone broke into her office and stole important documents from her safe. Office surveillance video footage later showed that Zhu was the culprit in the break-in.

She was soon contacted by Zhu, who told her that she had nine days to sign an agreement that gave him 50 percent of her company or face the consequences, the report said.

Wei refused to sign the agreement. She later found that someone had smashed up her Mercedes-Benz. After she sent it in for repairs, the repairmen found that someone had secretly installed a global positioning system (GPS) device inside her car.

The GPS system was paired with a mobile phone card that could work to record any sound inside the car when the phone number was called.

Wei also found that someone had secretly installed monitoring software on her computer.

After a few days, a post emerged online that contained rumors about Wei.

Someone also sent letters to Wei's clients and the government regulator that oversaw her company. The letters also contained rumors about Wei, causing her to postpone plans for her company's initial public offering.

The news report did not say what the rumors said, other than that they were untrue and confusing.

Wei reported the matter to police, who discovered that surveillance equipment had been installed in her office, bedroom and luggage. Monitoring software had also been installed on her office computer and mobile phone.

Police found that the software captured a screenshot of Wei's computer every five minutes, which was then forwarded to Zhu's e-mail address.