“The ICAC has a different jurisdiction under a different set of laws, but obviously when there’s something in common we both are investigating ... we found that this time it has been extremely useful to combine forces,” Alder told the Post on the sidelines of a charity event.

The SFC boss was abseiling 1,000 feet down the side of One Island East in Tai Koo on Saturday as one of 35 daredevils who raised more than HK$2.5 million (US$320,000) for Outward Bound Hong Kong, a charity which organises outdoor activities for the young and disabled.

“We can’t reveal exactly why, but I think it was very significant actually that we worked together, which I think would set the scene for future investigations,” Alder said of the probe.

The two bodies usually conduct separate investigations as the relevant laws they operate under are different.

The ICAC is given legal powers to investigate corruption under three main ordinances: the Independent Commission Against Corruption Ordinance, the Prevention of Bribery Ordinance and the Elections Ordinance, whereas the SFC regulates the stock market under the Securities and Futures Ordinance.

ICAC arrests Convoy chairman at the airport as investigation expands to involve Lerado

Hong Kong’s financial authorities have been stepping up efforts to crack down on malfeasance, turning the spotlight particularly on the so-called con stocks – a group of interconnected, closely held penny stocks that entrap minority shareholders – to make the city’s capital market safer and more attractive to investors.

On Thursday the ICAC for the first time joined hands with the SFC to raid offices and other premises in eight locations, according to an ICAC statement.

Four senior executives have so far been arrested by graft-busters over suspected corruption in relation to the case, according to announcements from individual companies.

Convoy confirmed that its chairman Quincy Wong Lee-man and two senior executives, Rosetta Fong Sut-sam and Christine Chan Lai-yee, had been taken in, while Lerado Financial Group’s current chairman Mark Mak Kwong-yiu, who was chief executive of Convoy until last year, was also arrested.

Convoy group president Ng Wing-fai sent a letter to customers on Friday assuring them their rights remained unchanged and the company remained financially stable.

Although Alder declined to comment further on the case as it was under investigation, he said it was “really encouraging” that the two agencies had “worked really, really well together”, as they contributed different skill sets and came with different objectives.

He would not say whether there would be more joint operations, but said it was “obvious” there would be circumstances where it would be appropriate.

Meanwhile, Secretary for Financial Services and the Treasury James Lau rejected suggestions that regulatory authorities had taken action in response to a list of companies named by independent analyst and shareholder activist David Webb.

“Of course it is not the case [that we followed suit] according to the list,” Lau said. “The SFC has their own channels – they receive complaints and have their own close monitoring and investigative direction.”

Webb published a list titled 50 Stocks Not to Own on his website in May, warning that such locally listed companies were “known bubbles” which the SFC had issued warnings on.

Convoy and Lerado were both named in what Webb called an Enigma Network of companies. Another named firm, Town Health International Medical Group, was recently ordered by the SFC to suspend trading in its shares on November 27. The company’s executive deputy chairman, Cho Kwai-chee, is also an executive director at Convoy.