Samsung Group chairman Lee Kun-hee passed away on Sunday at the age of 78, the company reports.

Lee was confined to a sick bed for six years due to heart problems.

Charismatic Lee turned Samsung into South Korea's largest multinational corporation and a global market leader in smartphones, semiconductors and televisions.

He was South Korea's richest person with about $ 20.9 billion in assets, according to

Forbes

.

"His legacy will last forever," Samsung said in response to his death.

But Lee was also controversial.

For example, he has been convicted of bribery and tax avoidance.

His company is also constantly under fire for the extraordinary economic power it still has in South Korea, a lack of transparency and dubious asset transfers within his family.

It is unclear who will succeed Lee.

His children have not agreed in the past six years on who the lion's share of his shares belong to.

Experts expect a battle between his heirs.

Samsung is a 'chaebol', a name used in South Korea for conglomerates controlled by different families.

This corporate structure helped rebuild the country quickly after the war, but has been widely criticized for its lack of transparency.

Lee Nak-yon, leader of the ruling party and former prime minister, praised Lee's leadership, but was also critical.

"It cannot be denied that he strengthened the chaebol economy and failed to recognize trade unions," said the politician.