SHANGHAI, China — An investigation into Zexi Investment chief Xu Xiang is examining whether he and the chairman of Shanghai Metersbonwe Fashion & Accessories Co. conspired to manipulate Metersbonwe shares ahead of last summer's market rout, according to a person familiar with the matter.

Xu, known in China as “Hedge Fund Brother No. 1,” was detained on Nov. 1 amid probes into stock trading following the 2015 market turmoil, which wiped out $5 trillion in market value between June and August. At the time of Xu’s detention, authorities froze about $1 billion of shares that Xu’s hedge fund held in listed companies.

Shanghai Metersbonwe Chairman Zhou Chengjian also has been detained as part of the probe, according to the person, who asked not to be identified because the matter hasn’t been made public. Authorities are trying to determine whether Zhou and Xu sought to raise the price of Shanghai Metersbonwe shares ahead of the sharp stock market decline, the person said.

The Shenzhen Stock Exchange said on Thursday that Zexi violated stock listing rules while it was a shareholder of Shanghai Metersbonwe.

No comment has been available from Zexi which, according to Shenzhen Rongzhi Investment Consultant Co., managed four of China’s top-10 performing hedge funds between June and August. On Thursday, calls to Zexi’s company phone could not go through, reaching only a message saying the number was not in service. Two of Xu’s cellphones were powered off.

Calls to Shanghai Metersbonwe offices were not answered.

Corruption checks are taking place across China’s financial industry as the Communist Party’s Central Commission for Discipline Inspection vets regulators, the nation’s biggest banks, and sovereign-wealth fund China Investment Corp. In addition, investigations following the stock market rout have entangled executives from Citic Securities Co., the nation’s top brokerage, and a senior official at the China Securities Regulatory Commission.

By Steven Yang and Keith Zhai; editors: John Liu and Ken Wills.