Hong Kong's former leader Donald Tsang, who ended his term in disgrace after accepting favours from tycoons, appeared in court Monday charged with misconduct in the latest high-profile corruption case to hit the city.

Tsang, 70, has been under investigation by the city's Independent Commission Against Corruption (ICAC) since he left office in June 2012.

He was released at magistrates' court on cash bail of HK$100,000 ($13,000) and will appear again on November 13.

Grim-faced and wearing a trademark bow-tie, Tsang spoke only to confirm he understood the two misconduct charges.

He held the leadership post of chief executive for seven years from 2005 and would become the highest-ranking Hong Kong official to face a corruption trial.

Speaking outside court, he insisted his "conscience is clear".

"I have every confidence that the court will exonerate me at the end of its proceedings," he said.

His wife Selina who accompanied him said she was "deeply disheartened" by the case.

"We longed for peace and tranquillity in retirement... instead we now find ourselves dragged into a whirlpool," she said.

The charges relate to Tsang's failure to disclose his plans to lease a luxury flat in the southern Chinese city of Shenzhen which was owned by a major investor in a broadcaster seeking a licence from the Hong Kong government, the ICAC said.

Tsang also failed to declare that an architect he proposed for a government award was employed as an interior designer on the flat, the ICAC added.

- Corruption crackdown -

The case comes less than a year after Hong Kong property tycoon Thomas Kwok and the government's former deputy leader Rafael Hui were jailed for graft, after Hui was found guilty of taking bribes from Kwok and Kwok's brother Raymond.

Hong Kong has been seen as relatively graft-free. But new cases in the semi-autonomous Chinese city have fuelled public suspicions over cosy links between authorities and business leaders.

Concerns have also been raised about the role of the Chinese system of personal connections, or "guanxi", which greases the wheels of business.

"The ICAC has been criticised for dragging its feet over the Donald Tsang case, so it's a way to improve the ICAC's image that they are picking on what the Chinese call the 'big tigers'," said political analyst Willy Lam of the Chinese University of Hong Kong.

"But there are still cases pending."

There are questions over why a complaint lodged with the ICAC against current leader Leung Chun-ying has not progressed, said Lam.

That case relates to a payment to Leung of HK$50 million by an Australian firm just before he took office.

The fact that the ICAC is overseen by the chief executive has also raised concerns, added Lam, who said any prosecutions would likely have been sanctioned by Beijing.

Chinese President Xi Jinping has launched a wide-ranging anti-corruption drive on the mainland.

"One theory is that Beijing wants to demonstrate that it is in charge of Hong Kong... they have decided to come down hard on the former chief executive," said Lam.

Secretary for Justice Rimsky Yuen said there was no political motive.

"I can unequivocally clarify there is absolutely no political consideration," he told reporters.

"We should not view the incident negatively... it shows Hong Kong's existing rule of law and the legal system are still intact," he added.

While serving as chief secretary for administration, Hui was Tsang's deputy from 2005 to 2007.

He was jailed in December for seven and a half years on a total of five graft charges, making him the highest-ranking official in the city's history to be found guilty of taking bribes.