The probe into last October's penny stock rout on the Singapore Exchange (SGX) has now widened to include the chief executive of Innopac Holdings as well as units of Magnus Energy.

The Commercial Affairs Department (CAD) has asked Mr Wong Chin-Yong, CEO and executive director of Innopac Holdings, to assist with investigations in relation to offences under the Securities and Futures Act.

Meanwhile, Magnus Energy Group also announced that two subsidiaries and a former subsidiary had received notices from CAD to provide all information and data belonging to the company's executive director Koh Teng Kiat and chief financial officer Luke Ho Khee Yong.

Asiasons Capital issued a statement on SGX on Thursday clarifying that neither the company and its subsidiaries, nor any of its directors and officers have received notices from any authorities to assist with the investigation.

It added there had been no request for documents or electronic records.

"The CAD and MAS's investigations pertain to the trading irregularities of shares in the three companies and do not pertain to the business operations of the Asiasons Group which remains unaffected," the company said.

The CAD and Monetary Authority of Singapore (MAS) said on Wednesday they are investigating possible violations of the Securities and Futures Act involving Asiasons Capital, Blumont Group and LionGold Corp.

The shares of the trio rose between 40 and 160 per cent in August and September last year, but then plunged between 91 and 96 per cent over a few days in October, knocking off more than $8 billion in market value combined.