Hong Kong anti-corruption police have searched the home of a media magnate who owns a popular pro-democracy newspaper and is known as a critic of Beijing.

Officers from the Independent Commission Against Corruption visited the home of Jimmy Lai on Thursday morning.

The timing raised eyebrows because it comes days before a key decision by Beijing on direct elections for the leader of Hong Kong, a specially administered Chinese region.

Lai told reporters camped outside his home in an upscale neighborhood that "ICAC was here" but have since left. He did not comment further.

An ICAC spokeswoman said the agency would not comment on individual cases.

Shares of Lai's company, Next Media, have been suspended from trading on the Hong Kong stock exchange.