Pearl Oriental Oil (0632), of which Lew Mon-hung is vice chairman, is understood to be at the center of an ongoing investigation by the Independent Commission Against Corruption.
Lew last night admitted he and chairman Wong Kwan had been arrested by the ICAC on January 8 and are both now on bail.
This came as the company said it is in the process of securing a new auditor after Grant Thornton Hong Kong resigned from the post on Friday.
The stock last traded at HK$0.63 on January 8, when it was suspended pending the release of an announcement "in relation to inside information."
On the day, rumors surfaced about Wong being questioned by the ICAC.
Lew told reporters he had no idea of Wong's whereabouts after he failed to show up at a scheduled tea gathering.
Wong holds a 24.63 percent stake in Pearl Oriental to Lew's 5.65 percent holding as of June 30.
Last month, the firm said it may buy up to 83 percent of Toronto-listed energy firm Petrox Resources, which has potential oil reserves of 160 million barrels.
Last week, Wong declared to the media that he was fine but added: "My company has been facing tough challenges." He then added: "I will try my best to sail through."
Lew was appointed as vice chairman of Pearl Oriental at the end of 2009.
It is believed his biggest contribution to the company was raising HK$500 million for the acquisition of overseas gas fields.
Lew has been active in the foreign exchange and futures markets for a long time and served as chairman of several listed companies in the past.
Wong also used to be very a high- profile person. But he has become less so in recent years. His last public appearance was at a November 2011 function to support Chief Executive Leung Chun- ying's election campaign.
It is believed Wong had been persuaded by Lew to attend the event.
Wong, 64, said he has known Leung for two decades as both were in the property business.
Before tapping the natural resources sector, Wong was active in property investment, which turned him into a billionaire in the 1980s and 1990s.
The cook-turned businessman bought two well-known homes on The Peak in 1996, only to sell them at huge losses after the Asian financial crisis.
One of the homes was bought by comedian Stephen Chow Sing-chi.
Both Lew and Wong are from humble backgrounds and came to Hong Kong from the mainland when young. They are said to have remained friends.