Cho Hyun-ah, also known as Heather Cho, daughter of chairman of Korean Air Lines, Cho Yang-ho, is surrounded by media upon her arrival at the Seoul Western District Prosecutor's Office in Seoul December 17, 2014. South Korea's transport ministry said on T
Cho Hyun-ah, also known as Heather Cho, daughter of chairman of Korean Air Lines, Cho Yang-ho, is surrounded by media upon her arrival at the Seoul Western District Prosecutor's Office in Seoul December 17, 2014. South Korea's transport ministry said on Tuesday it would report to prosecutors a former Korean Air Lines executive who delayed a flight earlier this month because she was unhappy about how she was served nuts.REUTERS/Kim Hong-Ji (SOUTH KOREA - Tags: TRANSPORT BUSINESS CRIME LAW)
Cho Hyun-ah, also known as Heather Cho, daughter of chairman of Korean Air Lines, Cho Yang-ho, is surrounded by media upon her arrival at the Seoul Western District Prosecutor's Office in Seoul December 17, 2014. South Korea's transport ministry said on Tuesday it would report to prosecutors a former Korean Air Lines executive who delayed a flight earlier this month because she was unhappy about how she was served nuts.REUTERS/Kim Hong-Ji (SOUTH KOREA - Tags: TRANSPORT BUSINESS CRIME LAW)

The macadamia nut industry has resigned Korea Air Vice President Heather Cho to thank for because her air rage over being served the nuts in a plastic bag instead of a plate saw a large increase in demand for the controversial nut in South Korea.

However, while the nuts are a hot item in Seoul and other South Korean cities, the country's Transport Ministry is hot on the trail of four South Korean officials for improper conduct while investigating Cho, reports Chron.com.

The uproar is due to leaked information and other improper acts, said Shin Eun-chul, who headed the internal investigation conducted by the ministry. He said the ministry had issued warnings to the four officials.

One of the was arrested on Friday because he allegedly leaked information about the ongoing investigation to an incumbent Korean Air executive who has the surname Yeo, using text messages and phone calls.

The three other officials allowed Yeo to attend the questioning session of the purser whom Cho ordered to leave the plane, which delayed the flight's departure and arrival. The officials also didn't interview other business class passengers who could testify that Cho threatened and assaulted the flight attendant.

Cho, even if she has resigned out of shame over the incident, is not yet off the hook. A Seoul court is considering issuing a warrant for her arrest. Prosecutors also want Yeo arrested for pressuring Korean Air employees to cover up the macadamia nut scandal.

Meanwhile, South Koreans have gone nuts over macadamias after the incident. John Cross from the Hawaii Macadamia Nut Association said that its second-largest processor received three phone calls from Korean brokers to place an order for the confection days after the incident. He said there was a 300 percent hike in inquiries from Korea in one of the association's processors.

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Cross added, quoted by Radio Australia, "From what we're hearing, the Korean stores, the stores that stock product, it's flying off the shelves and so there's a demand for product coming out of Hawaii."

Until Cho's air rage, macadamias were relatively unknown in Korea, Cross said.

To contact the writer, email: v.hernandez@ibtimes.com.au