HONG KONG • Mr Walter Kwok, the former chairman of Hong Kong real-estate developer Sun Hung Kai Properties, died last Saturday morning at the age of 68, according to a statement from his family.

"We are saddened to announce the passing of Mr Walter Kwok, who left this world peacefully on the morning of Oct 20, with his loving family by his bedside," the statement said.

It added that church service arrangements would be announced in due course. It did not disclose details of Mr Kwok's death.

Mr Kwok suffered a heart attack on Aug 27 and was transferred to Hong Kong's Adventist Hospital, according to local media reports.

He was the oldest of three sons who inherited the fortune of Mr Kwok Tak Seng, a grocery wholesaler from Guangdong province in China who migrated to Hong Kong after World War II.

Mr Kwok Tak Seng joined Mr Fung King Hey and Mr Lee Shau Kee to found Sun Hung Kai Properties in 1963.

The company sold shares in an initial public offering in Hong Kong in August 1972 and became one of the world's largest real-estate developers by market value. Sun Hung Kai's business has stretched into other areas, including logistics and telecommunications.

The three sons - Walter, Thomas and Raymond - took over the company after their father died of a heart attack in 1990.

Walter, also known by his Chinese name Ping Sheung, ran the company until 2008.

He was kidnapped in 1997 by a Hong Kong gang leader nicknamed "Big Spender", who also held Hong Kong billionaire Li Ka Shing's son Victor for ransom.

A public family squabble led to Walter's extended leave and, subsequently, his ouster as chairman in 2008. Walter said Thomas and Raymond had him removed from his position because they thought he was suffering from a mental illness, which he had denied.

Hong Kong's Standard newspaper reported that Walter was forced to go on leave after a disagreement with his brothers over a female friend's growing influence in the company. He later sued his siblings for libel.

Their mother, Ms Kwong Siu Hing, took over as chairman, and Thomas and Raymond later became co-chairmen of Sun Hung Kai.

Walter applied to the High Court in 2008 to prevent the board from removing him from his post, alleging that his brothers opposed his questioning of the way the company awarded construction contracts, and other corporate governance issues. Walter and the family settled their dispute amicably in January 2014.

In 2010, Walter began pursuing his own property projects with his company Empire Group Holdings.

Empire this year was awarded a redevelopment project in tourist area Tsim Sha Tsui, on which it planned to spend HK$6 billion (S$1.1 billion), according to the South China Morning Post.

Thomas and Raymond were arrested in March 2012 by Hong Kong's anti-graft agency, and were charged with bribery and misconduct four months later.

According to the Independent Commission Against Corruption, Thomas, Raymond and two other men conspired to provide Rafael Hui, the city's former No. 2 government official, with free use of two apartments and two unsecured loans for unspecified favours. The Kwoks denied any wrongdoing and pleaded not guilty in March 2013.

The company later named Mr Adam Kwok, Thomas' son, and Mr Edward Kwok, Raymond's son, as alternate directors.

Thomas was sentenced to five years' jail in 2014 and lost an appeal last year. His brother Raymond was found not guilty.

BLOOMBERG