Twenty people, including executive directors of two publicly listed companies, have been arrested for alleged corruption in relation to suspected share-price manipulation and share placement.

A financial controller and three other employees of one of the listed companies, and an executive director of the listed company's subsidiary were also arrested in the operation - codenamed "Mobidick" - that started on Wednesday.

The others who were arrested included an investment adviser, a fund manager, a research executive, a director, and a securities broker of four financial institutions, as well as eight other individuals.

The ICAC received information earlier, alleging that a listed company's executive director had conspired with other people to bribe fund managers for arranging to use the funds they managed to buy large tranches of the listed company's shares, and publishing a favourable research report on the company.

Corrupt deal triggers $2m in 'rewards'

Investigations revealed that in July last year, a director and investment adviser of a financial institution arranged a deal between the executive director of one of the listed companies and a fund manager to buy in more than 10 million of the company's shares.

It is suspected that more than $2 million had been shared between the fund manager and the two middlemen as rewards.

It was also alleged that the arrested executive director of the listed company had offered a cash payment to a research executive of another financial institution to have it publish a favourable research report on the listed company.

Staff, associates alleged to have manipulated stock prices

The executive director was further alleged to have engaged his employees and associates to fraudulently manipulate the listed company's share prices.

Suspected bribe money of more than $6 million in cash, and a luxury saloon allegedly bought with the suspected corrupt proceeds, were seized during the operation.

Meanwhile, the other listed company's executive director and a securities broker were arrested for suspected corruption in relation to share placement.

The ICAC is detaining eight of the arrested people while the rest have been released on bail. Inquiries are continuing.