The acting national police chief apologized Friday for the growing controversy over the alleged leak of investigative information and possible destruction of evidence in a high-profile murder case by police investigators themselves. Yoo Jae-sung, acting chief of the Korean National Police Agency, speaks to reporters at the Incheon International Airport on July 10. (Yonhap) Acting National Police Agency Commissioner Yoo Jae-seong made the apology at Incheon International Airport immediately after returning home from the United States, where he attended the United Nations Chiefs of Police Summit. The acting head of the national police agency cut short his U.S. trip that was originally scheduled to end Saturday."I am very sorry for causing concern to the public," he told reporters, noting that he was aware of the gravity of the issue.Allegations have recently intensified over possible ties between local investigators and the father of the suspect in the case, accused of killing a 17-year-old female student and attempting to murder a 17-year-old male student in the southwestern city of Gwangju in May.The suspect's father serves as a police officer in the city.Multiple police officers at Gwangju's Gwangsan Police Station have come under investigation on suspicions of leaking investigative information and destroying evidence related to the case. (Yonhap)