China has further extended its control of the Internet within its borders.

Chinese and Hong Kong media report that Lu Wei, former head of the Cyberspace Administration of China, was detained by security forces in recent days. It has also emerged that Skype, the Microsoft-owned messaging and calling service, has become unavailable in China.

Lu, head of the CAC from 2013 to 2016, was the ultimate authority who decided whether foreign tech companies could operate in China. He was lobbied by Amazon’s Jeff Bezos, Facebook’s Mark Zuckerberg, and Apple’s Tim Cook. Amazon and Facebook remain banned from China.

Lu lost his job last year but kept his position as deputy director of the Communist Party’s Propaganda Department until this month. He was succeeded at the CAC by Xu Lin, a member of the party’s powerful Central Committee.

In a statement, the party’s Central Commission for Discipline Inspection said Lu was being “questioned for suspected serious violations of party discipline.” That description is usually code for corruption. The commission did not elaborate on Lu’s alleged misdeeds.

Skype was removed from Apple’s app store in China and from the download sites operated by Tencent and Qihoo in recent days. Disruption to Skype began in October.

“We have been notified by the Ministry of Public Security that a number of voice-over-Internet-protocol apps do not comply with local law. Therefore these apps have been removed from the app store in China,” an Apple spokeswoman told the Reuters news agency.

Chinese authorities have spent much of the past year expanding government control over the Internet. Western tech services including Facebook, Twitter, and Google have long been excluded. This year the government has ordered the removal of downloads for virtual private networks and intervened to disrupt the operation of VPNs. In recent weeks it has used technological means to block WhatsApp, the Facebook-owned messaging services that uses encryption technology to keep content private.

The Chinese government, which introduced new cyberspace laws this summer, requires tech companies to give it access to their servers and keep data in China. It recently imposed maximum fines on Chinese companies Baidu, Tencent and Weibo for not doing enough to censor user-generated content posted on their sites.