Kwok brothers held by anti-corruption investigators, wiping billions of dollars off value of their property company.

The brothers behind Hong Kong’s largest property developer have been arrested on suspicion of corruption, the company has confirmed.

Brothers Raymond and Thomas Kwok, who serve as co-chairmen and managing directors of Sun Hung Kai Properties, were detained on Friday by anti-corruption investigators over alleged bribery offences.

A company statement said the Kwoks would continue with their duties, and that normal business operations would not be affected.

The Independent Commission Against Corruption (ICAC), which did not confirm the identity of the suspects, also said it had arrested a former senior govenment official.

The South China Morning Post newspaper identified him as former chief secretary Rafael Hui, who had worked as a special adviser to Sun Hung Kai.

On its website, the ICAC said the arrests were linked to “alleged offences under the prevention of bribery ordinance and misconduct in public office”.

“Two senior executives of a listed company in Hong Kong and a former principal official of the Hong Kong Government have been arrested for suspected corruption,” it said in a statement.

Gary Plowman, a former government prosecutor, said he had been to the ICAC and was representing one of the arrested parties whom he declined to identify.

“Nobody has been charged,” Plowman said. “We react, we’re not proactive. We are reactive in these situations,” he said.

The ICAC was set up in 1974 to root out what was seen as widespread corruption in the Hong Kong government at the time, especially in the police.

It acts as a law-enforcement agency, able to arrest and detain suspects, and prosecutes cases in conjunction with advice from the department of justice.

Shares in Sun Hung Kai Properties lost almost $5bn in value following the arrests, plunging more than 13 per cent.