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.

Metersbonwe Chairman Zhou Chengjian also has been detained as part of the probe, according to the person, who asked not to be identified. Authorities are trying to determine whether Zhou and Xu sought to raise the price of 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 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.