A parliamentary committee held a hearing Tuesday to look into allegations that the presidential office interfered in a probe into a large-scale drug smuggling case to cover up the involvement of customs officials.During a plenary session of the public administration and security committee, the ruling People Power Party and the main opposition Democratic Party (DP) offered differing views, with the DP claiming the presidential office had exerted pressure over the investigation."Through the hearing, we should reveal who exerted pressure on the drug investigation and who led and instructed the pressure," DP Rep. Youn Kun-young said.He added that Baek Hae-ryong, then head of the investigation team at the Yeongdeungpo Police Station, said he clearly heard the word "Yongsan," commonly referred to as the presidential office, in his phone talks with Kim Chan-su, former chief of Yeongdeungpo police.Kim denied such allegations at the session when asked whether he had mentioned that the presidential office is " aware and considering the case seriously."Baek earlier said he was about to give a press briefing on the involvement of the customs officials but was pressured by senior officials to leave out any mention of "Korea Customs Service" from the briefing.South Korean customs officials allegedly helped Malaysian smugglers bring methamphetamine into the country via Incheon International Airport, west of Seoul, in January last year.Source: Yonhap News Agency