Jakarta. National Democratic Party (Nasdem) politician Erik Adtrada Ritonga, the current regent of Labuhanbatu in North Sumatra, was named a suspect on Friday for allegedly accepting bribes.

The announcement by the Corruption Eradication Commission (KPK) came a day after he was arrested in an anti-graft bust in the regency along with several other individuals.

Three other detainees were also designated as corruption suspects, including Rudi Syahputra, a member of the Labuhanbatu Legislative Council, and two businessmen identified as Fajar Syahputra and Effendi Sahputra. 

The four suspects were officially put under KPK custody for the next 20 days, KPK Deputy Chairman Nurul Ghufron said in a news conference in Jakarta.

All the suspects were presented in the conference, dressed in orange detainee vests and handcuffed.

During the raid in Labuhanbatu, KPK investigators seized banknotes worth Rp 551.5 million ($35,400) from the suspects. 

Nurul said the operation followed a tipoff about suspected payment to officials intended to fix the bidding for a local government project,

"Investigators seized banknotes worth Rp 551.5 million -- allegedly part of a total payment of Rp 1.7 billion," Nurul said.

Erik is the third state official from Nasdem to be implicated in corruption cases in recent months, after former Communication and Informatics Minister Johnny Plate and former Agriculture Minister Syahrul Yasin Limpo.