Hong Kong's former leader Donald Tsang, who ended his term in disgrace after accepting favours from tycoons, pleaded not guilty to bribery charges Tuesday at his high-profile corruption trial.

Tsang, 72, held the leadership post of chief executive for seven years from 2005 and is the highest-ranking Hong Kong official to face a corruption trial.

The case is set to send shockwaves through a city that has earned a reputation as one of the world's most open and transparent markets.

Wearing his customary suit and bow-tie, a somber-looking Tsang arrived hand-in-hand with his wife at the city's High Court over an hour before the hearing was scheduled to begin Tuesday morning.

He pleaded "not guilty" to three charges of misconduct and bribery. Each charge carries a maximum jail sentence of seven years.

The charges pertain to the period when Tsang was chief executive.

He is accused of failing to disclose his plans to lease a luxury penthouse in the neighbouring city of Shenzhen from a major investor in a broadcaster -- which at the time was seeking a licence from the Hong Kong government.

Tsang allegedly approved the company's application for the licence, and also failed to declare that an architect he proposed for a government award had been employed as an interior designer on the flat.

The hearing is expected to last 20 days.

He has previously said that he had "every confidence" he would be exonerated. 

In 2012 he apologised for separate allegations that he accepted inappropriate gifts from business friends in the form of trips on luxury yachts and private jets.

The trial comes at a time when residents are losing faith in Hong Kong's leaders, as a string of high-profile corruption cases fuel public suspicions over cosy links between authorities and business leaders.

Critics blame the city's method of electing its leader -- who is selected by a 1,200-strong electoral committee made up of representatives of special interest groups weighted towards Beijing.

"I strongly believe that the chief executive has to (maintain) close relations with special interest groups and tycoons," pro-democracy lawmaker Lam Cheuk-ting told AFP.

"It is very dangerous and very difficult to remain independent from those... groups," said Lam, a former investigator for the Independent Commission Against Corruption, the city's anti-graft agency.

"Tsang's case is just the tip of the iceberg," he added.

Hong Kong's unpopular current leader Leung Chun-ying also faces allegations of corruption over receiving a reported payment of HK$50 million ($6.5 million) from Australian engineering firm UGL before he took office.

Experts say the case sends a message that the judiciary is not afraid to go after high-ranking officials.

"It (Tsang's case) sets a precedent because the current chief executive is also involved in allegations of corruption," political expert Ma Ngok told AFP.

"That would create a public expectation that a case may be launched against Leung when he finishes his term," Ma, a professor at the Chinese University of Hong Kong said.

In 2014, Tsang's deputy Rafael Hui was jailed for seven-and-a-half years after being found guilty of taking bribes from Hong Kong property tycoon Thomas Kwok.

Source: AFP