Cho Hyun-min Korean Air
Cho Hyun-min, a former Korean Air senior executive and the younger daughter of the airline's chairman Cho Yang-ho, arrives at a police station in Seoul, South Korea, May 1, 2018. REUTERS/Kim Hong-Ji

A Korean Air heiress apologised for causing trouble in her first public appearance as a suspect in an abuse of power case after she allegedly threw a drink at someone during a business meeting.

The police questioning of Cho Hyun-min, a former senior president at Korean Air, comes amid mounting pressure for elite families to scale back their influence over the companies founded by their relatives decades ago.

"I'm sorry for causing troubles," Cho said, seemingly fighting back tears and then bowing her head while speaking with reporters outside police offices in an appearance that TV networks broadcast live.

She repeated the phrase when a reporter asked for her thoughts about calls for her family to relinquish their influence over the group of companies they control.

Cho, 35, oversaw marketing and advertising at the South Korean flag carrier, a company founded by her grandfather. Korean Air Chairman Cho Yang-ho, her father, sought to appease critics by announcing the resignation of his two daughters from their executive positions last month.

The scandal over her behaviour was not the first.

Cho's elder sister gained worldwide notoriety for pitching a tantrum on board a Korean Air flight that forced the aircraft to return to an airport gate in 2014.

Cho Hyun-ah, 44, who at the time was in charge of the airline's cabin service, grew angry when a first-class flight attendant served her nuts in a bag instead of on a dish. The plane was forced to return to the gate at New York's John F. Kennedy Airport.

She was released from jail after a South Korea's appeals court suspended her prison term for coercion and obstruction of business and briefly returned to management at a Korean Air affiliate before resigning last month.

The latest problems snowballed to engulf the Cho family as Korean Air employees accused the family of other alleged wrongdoing.

Whistleblowers have alleged that the Chos, who hold a minority stake in the publicly listed airline, have assaulted workers who angered the family.

The Korea Customs Service is investigating allegations of smuggling and tariff evasion following claims that the family bought luxury goods abroad and avoided paying duties on them by portraying the imported items as supplies for Korean Air aircraft.

The allegations have incensed the public as local media reported leaked voice recordings and videos purporting to show Cho family members mistreating Korean Air employees.

When he took office in 2017, South Korean President Moon Jae-in promised to work to curb the influence of founding families of the country's big chaebol, or huge conglomerates like Samsung, Hyundai and Korean Air that dominate the South Korean economy.

South Koreans revere the entrepreneurs like Cho's grandfather who helped build the country's economy from the ashes of the 1959-53 Korean War. But they tend to take a dim view of outlandish and illegal behaviour by their heirs.