The founder of South Korea's sprawling retail conglomerate Lotte Group has died at the age of 97, company officials said Sunday.

Shin Kyuk-ho's reputation was tarnished in his final years when the wheelchair-bound tycoon was convicted of professional malpractice and embezzling from the firm to benefit his relatives in late 2017.

He was sentenced to four years in prison but was allowed to stay out of jail on health grounds.

Born in the southern city of Ulsan, Shin stowed away on a ship to Japan at the age of 18 to seek his fortune and established Lotte to manufacture chewing gum in Tokyo soon after World War II.

The business later grew to include dozens of subsidiaries in the food, retail and hotel industries.

Lotte is one of the biggest of the South Korean family-run "chaebol" conglomerates that powered the country's decades of runaway economic growth -- but which are sometimes accused of murky business practices and overly-close ties with politicians.

Shin's two sons made headlines in 2015 with a bitter public fight for control of the group, each accusing the other of mismanagement, personality flaws, and of manipulating their frail and aged father.

His younger son Dong-bin eventually took over the reins as chairman but both he and Shin were accused of causing $72 million in damages to the group by renting out Lotte Cinema concessions at discounted rates to the founder's eldest daughter and mistress.

The daughter was jailed for two years, while the mistress -- a former model and actress 39 years Shin's junior, who came to his attention after winning a beauty pageant -- was given a suspended sentence.

Shin was also found to have disposed of company assets in violation of his responsibilities as chairman by the presiding judge in his 2017 trial. He had been suffering from dementia and other diseases of old age before his death, according to South Korea's Yonhap news agency.