HONG KONG (AFP) - An embarrassed Hong Kong lawmaker has apologised after he was photographed looking at scantily-dressed pictures of models on his tablet computer during a Budget speech at the Chinese city's parliament.

Pro-democracy politician Albert Ho was snapped flipping through multiple photos of bikini-clad ladies while finance secretary John Tsang delivered a one-and-a-half-hour long Budget speech on Wednesday.

"It just so happened that at that time, I casually saw the photos," said Mr Ho, who failed in a bid to become Hong Kong's leader in 2012.

"I have learnt a lesson, I should not commit such a mistake again," he told reporters on Wednesday, adding that he had apologised for the incident.

Photographs published in local media showed Mr Ho in the legislative chamber holding up the screen cover of his iPad tablet, apparently in an attempt to conceal what he was doing, while swiping through the photos.

The South China Morning Post reported that the lawmaker, who was for a time the chairman of the city's largest pro-democracy party, browsed through the photos for 10 minutes.

Mr Ho is not the first lawmaker to be left red-faced after being distracted during parliamentary business.

In 2011, an Indonesia lawmaker from a conservative Islamic party resigned after he was photographed looking at pornography on his tablet computer in parliament.

In 2003, Hong Kong's then education minister Arthur Li was spotted playing a video game in parliament while last year lawmaker Eddie Ng was seen checking stock market updates on his phone during a question-and-answer session with the chief executive.