A former leader of Hong Kong was sentenced to 20 months in prison for misconduct after failing to disclose plans to rent a luxury apartment for his retirement from a businessman applying for a broadcasting licence.

High Court Judge Andrew Chan said on Wednesday that it was a stunning downfall for Donald Tsang, 72, who served as Hong Kong's leader, or chief executive, from 2005 to 2012.

He becomes the highest-ranking current or former official sent to prison for wrongdoing in the Asian financial hub, which prides itself on a reputation for clean governance.

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"Never in my judicial career have I seen a man fallen from such a height," Chan said as he handed down the sentence in a Hong Kong court. "However, it is not in dispute that the defendant has dedicated himself to public service for the past 40 years."

The judge said he was going to give Tsang 30 months in jail but took off 10 months because of his good character and contribution to Hong Kong. The maximum penalty for misconduct is seven years.

Tsang showed little emotion as the sentence was read out in a packed courtroom.

Chan noted that among Tsang's major contributions to public service, one that stood out was "his effort in overcoming" the 1997-98 Asian financial crisis.

Tsang, who was financial secretary at the time, led the city's successful defence of its currency peg against speculators.

A jury found Tsang guilty last week of one count of misconduct in public office but not guilty on a second count.

It's one of several recent cases that have shaken public confidence and raised concerns about cozy ties between Hong Kong's leaders and wealthy tycoons.

Jurors ruled 8-1 that he committed misconduct when he failed to disclose that the penthouse in neighbouring Shenzhen in mainland China was owned by a businessman whose company was applying for a digital radio licence.

They unanimously cleared him of the second misconduct charge, which alleged he failed to reveal he had nominated for an award an interior designer working on the penthouse's renovations.

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The jury couldn't decide on a third charge of accepting an advantage. A retrial is tentatively scheduled for September.

Outside the court, Tsang's wife Selina said that her husband would appeal against the verdict.

"Today is a very dark day," she told reporters. "My family and I are very disappointed and sad at the court's decision today.

"Donald and I have been greatly troubled and felt immense pressure in the past five years. So we are very sad about today's outcome. But we will face it with strength and courage. We will appeal."

Source: News agencies