Police said Friday they would look into the heiress of Korean Air’s alleged assault at a company meeting, where she is suspected of throwing a cup of water at an employee of an advertisement company last month.

Seoul’s Gangseo Police Station launched a preliminary investigation to determine whether there are enough grounds for violations of laws subject to formal investigation. 

The incident surfaced online Thursday after an anonymous writer accused Cho Hyun-min, executive director of Korean Air and the second daughter of Hanjin Group Chairman Cho Yang-ho, of throwing water in the face of an employee. She reportedly lost her temper after the manager could not answer a question about a Korean Air advertisement. 

Korean Air said Cho is currently overseas. Cho also uploaded a picture inside a plane Friday to her Instagram.

Cho is the younger sister of Cho Hyun-ah, who is known for her “nut rage” tantrum that sparked international uproar in 2014. The elder Cho recently made a return to management as president of KAL Hotel Network, after receiving a suspended sentence last year. 

As of Friday noon, over 5,000 people had joined online petitions at the Cheong Wa Dae website demanding authorities punish the younger Cho over her action, as well as remove Korean Air from the national carrier slot.

Cho, 36, also known as Emily Cho, made a public apology via her Facebook account Thursday.

“I apologize with my head down for my foolish and reckless behavior,” she wrote. “I have no words to say for my action that I should not have done under any circumstances.

A Korean Air spokesman said Cho was angry with the employee but denied that a cup of water was thrown at him. The company said “a water bottle was thrown on the floor, not at the manager’s face.”

By Kim Da-sol (ddd@heraldcorp.com)