Cho Hyun-ah, center, bows before entering a Korea Immigration Service office for questioning in Seoul, South Korea, Thursday, May 24, 2018. Cho, the Korean Air heiress whose tantrum over nuts delayed... (Associated Press) 
 
 SEOUL, South Korea (AP) — A Korean Air heiress whose tantrum over nuts delayed a flight nearly four years ago is being investigated by South Korean immigration officials on suspicion she unlawfully hired housekeepers from the Philippines. 
 
 Cho Hyun-ah on Thursday bowed and apologized for "causing troubles" before entering a Korea Immigration Service office in Seoul for questioning. 
 
 Cho and her sister resigned from their executive positions at Korean Air in April following public criticism over their behavior and allegations their family mistreated and abused employees. Investigators are also looking into suspicions that the Cho family, including the company's chairman Cho Yang-ho, evaded taxes and used airline services to smuggle luxury goods. 
 
 Cho's sister, Cho Hyun-min, is currently under investigation for allegedly hurling a cup of water during a business meeting. 
 
 In December 2014, Cho got angry after she was served macadamia nuts in a bag instead of on a dish and her tantrum forced the Korean Air plane to return to a boarding gate at New York's John F. Kennedy Airport. She was released from jail in South Korea in May 2015 after the top court suspended her sentence over the case. 
 
 Immigration officials suspect Cho and her mother, Lee Myeong-hee, unlawfully recruited and hired about 10 to 20 housekeepers from the Philippines by documenting them as Korean Air trainees. Under South Korean law, foreign nationals must obtain visas given to marriage migrants or people of Korean heritage to work as housekeepers. 

 Korean Air heiress Cho Hyun-ah appeared for a questioning at the Korea Immigration Service in Seoul at lunchtime Thursday, some three years after she made global headlines with the "nut rage" scandal. 
 
 This time, she is being questioned on charges of illegally hiring Filipino housemaids. 
 
 Cho and her mother Lee Myung-hee allegedly forged documents to disguise several Filipinos as vocational trainees for Korean Air but actually employed them as maids. 
 
 The Korea Immigration Service said it has testimony from Korean Air staffers who were questioned earlier in the snowballing scandal engulfing the family. 
 
 Cho and her mother apparently preferred foreign maids because they were concerned about their privacy if Koreans got too close a look at them. 
 
 The Korean Air owner family is under investigation over a series of allegations ranging from assault and abuse of staff to smuggling luxury goods.
– A newly unemployed Korean Air heiress whose tantrum over nuts delayed a flight nearly four years ago is being investigated by South Korean immigration officials on suspicion she unlawfully hired housekeepers from the Philippines. Cho Hyun-ah on Thursday bowed and apologized for "causing troubles" before entering a Korea Immigration Service office in Seoul for questioning. Cho and her sister resigned from their executive positions at Korean Air in April following public criticism over their behavior and allegations their family mistreated and abused employees, reports the AP. Investigators are also looking into suspicions that the Cho family, including the company's chairman Cho Yang-ho, evaded taxes and used airline services to smuggle luxury goods. Immigration officials suspect Cho and her mother, Lee Myeong-hee, unlawfully recruited and hired about 10 to 20 housekeepers from the Philippines by documenting them as Korean Air trainees. Chosun Ilbo reports that Cho and her mother preferred foreign maids over privacy concerns. Under South Korean law, foreign nationals must obtain visas given to marriage migrants or people of Korean heritage to work as housekeepers. Cho's sister, Cho Hyun-min, is currently under investigation for allegedly hurling a cup of water during a business meeting. In December 2014, Cho got angry after she was served macadamia nuts in a bag instead of on a dish and her tantrum forced the Korean Air plane to return to a boarding gate at New York's John F. Kennedy Airport. She was released from jail in South Korea in May 2015 after the top court suspended her sentence over the case.