The Malaysian Anti-Corruption Commission (MACC) says it has questioned the minister involved in the recent case of a traveller from China who did not meet the immigration conditions for entry into the country.
In a statement, it said the minister was one of three witnesses who had been questioned so far, alongside two Chinese nationals.
A number of immigration officers who were involved will also be called for questioning today.
A source said MACC had also identified an individual believed to have been the middleman in "resolving" the case, with efforts ongoing to track the agent said to have asked for a bribe of RM18,000.
"MACC takes a serious view of the corruption said to have taken place in the recent issue involving a Chinese national at KLIA," the agency said.
Tourism, Arts and Culture Minister Tiong King Sing became embroiled in controversy after intervening in the case of a Chinese woman who was detained at the airport for failing to fulfil visa requirements.
He accused immigration officers at KLIA of corruption and abuse of power, saying he was informed that immigration officers allegedly asked for money if detained foreign tourists wanted to be released.
"Some were asked up to RM3,000 to be released from custody, including a return ticket to their home country.
"An additional RM3,000 was required if they wanted to return to their home country through a 'special lane' and an expedited process, while RM12,000 was needed for visa processing costs," he said.
When contacted, MACC chief commissioner Azam Baki said the case was being investigated under Section 16 (a) of the MACC Act 2009.