The personal assets of Samsung Electronics Co. Chairman Lee Kun-hee, hospitalized over the weekend after a heart attack, are estimated at 12.9 trillion won ($12.5 billion), a tracker of corporate data said Tuesday, which could amount to up to 5 trillion won in inheritance taxes should those assets be handed over to his family members.

The 72-year-old tycoon, who effectively controls Samsung Group through a web of share cross-holdings of the group's affiliates, owns 11.7 trillion won worth of listed Samsung shares, along with

479 billion won in non-listed affiliates, according to Chaebul.com.

He also owns 678 billion won worth of real estate.

The value of listed shares were based on an average stock price between May 2013 and the same month this year. The worth of non-listed shares were calculated according to inheritance tax guidelines. Real estate holdings were priced according to their state-appraised value.

Lee and his immediate family members, who include his wife and three children, are worth at least 20.6 trillion won, according to the data.

The tycoon, the youngest of the three sons of Samsung founder Lee Byung-chull, had inherited much of his wealth from his father when he took over the conglomerate in 1987 after the founder's death.

Industry watchers say the inheritance tax on his assets, should they be passed on to his family members, could amount to anywhere between 3 trillion won and 5 trillion won.

The chairman's only son, Lee Jay-yong, has 3.9 trillion won of assets, including 1.2 trillion won in listed shares, data showed.

Of the two daughters, the elder, Lee Boo-jin, head of Hotel Shilla Co., owns 1.12 trillion won worth of assets, and Lee Seo-hyun, who leads the fashion division in Samsung Everland Inc., claims 1.06 trillion won.

Assets of his wife, Hong Ra-hee, director of Leeum, Samsung Museum of Art, were estimated at 1.5 trillion won, less than half of their son.

The wealth of the chairman, the country's richest man, came under renewed public attention after he was hospitalized for myocardial infarction, commonly referred to as a heart attack, over the weekend.

The Samsung Group is in the middle of major restructuring, viewed as a preparatory step for the managerial succession by Lee's children. (Yonhap)