Jakarta. The Corruption Eradication Commission (KPK) interrogated two former president directors of state-owned oil and gas company Pertamina on Tuesday as part of an ongoing corruption investigation involving a gas supply deal linked to one of its subsidiaries.

Former Pertamina CEOs Elia Massa Manik and Dwi Soetjipto were questioned as witnesses in an alleged graft case involving hundreds of billions of rupiah in state losses related to a sale and purchase agreement between Perusahaan Gas Negara (PGN) -- a Pertamina sub-holding specializing in gas supplies -- and a company named Inti Alasindo Energi.

Dwi served as Pertamina's CEO from 2014 to 2017, before being succeeded by Elia, who led the company from 2017 to 2018.

“There weren’t many questions directed at me because I served as CEO for only 13 months. When the sub-holding was formed, I was no longer in charge,” Elia said after his interrogation at the KPK headquarters in Jakarta.

Meanwhile, Dwi declined to answer media questions regarding his interrogation.

KPK spokesman Tessa Mahardhika said the official estimate of state losses is still being calculated by state auditors, and the commission has yet to name any suspects in the case.

Later this week, KPK plans to interrogate former Pertamina commissioner Edwin Hidayat Abdullah and former PGN commissioner Fajar Harry Sampurno.

On Monday, former State-Owned Enterprises Minister Rini Soemarno was also questioned as part of the investigation.

Rini said KPK investigators asked her about Pertamina’s leadership during her tenure as minister.

“I have forgotten some details because my tenure was over a decade ago,” she said.

She added that investigators also inquired about Pertamina’s acquisition of PGN in April 2018, to which she responded:

"The acquisition of PGN was purely a government policy," she said.