Baidu (NSDQ:BIDU), the operator of China’s most popular online search engine, has lost another artificial intelligence expert.

Lin Yuanqing, former director of Baidu’s institute of deep learning, confirmed reports that he resigned in September to launch his own AI company. The departure of Lin, who specializes in image recognition and human-computer interaction, provides the latest setback for Baidu as it attempts to bolster its business with AI technology while recovering from a 2016 regulatory scandal, the South China Morning Post reported last week.

In March, two other prominent Baidu executives, chief scientist Andrew Ng and Baidu founder Robin Li Yanhong, resigned the company. Baidu’s AI group has expanded to more than 1,300 workers in China and Silicon Valley, and Ng, who had worked at Baidu since 2014, oversaw most of that growth.

In January, Baidu enlisted former Microsoft (Nasdaq: MSFT) executive and AI specialist Lu Qi as its new chief operating officer.

New Street Research analyst Kirk Boodry has said Baidu’s core search business is under threat by social media and e-commerce companies leaving Baidu’s immediate future far from certain.

“Everyone in China internet has an AI focus, so Baidu does not really stand out,” he said. “AI is not a business model in itself. Baidu does appear to be a likely leader in autonomous driving but that will not be monetized before 2020 and it is not yet clear how that will be done.”

The defections at Baidu illustrate the high demand – and higher paychecks – for workers with expertise in AI. Both Ph.D.s fresh out of school and people with less education and just a few years of experience can earn between $300,000 and $500,000 annually, the New York Times reported.