The three companies have received investigation notices from the China Securities Regulatory Commission under its new chairman Xiao Gang.

Shanghai-listed Weifang Beida Jade Bird Huaguang Sci-Tech Co Ltd - a software provider based in Shandong province - received the investigation notice on Wednesday, although the commission still has to say on what ground the investigation was launched.

The company hit the 10 percent daily price-increase limit for three consecutive days last week.