At least five members of the National Assembly are being investigated by the prosecution for corruption. Although the five are implicated in three different cases, the probes are making the political community jittery because it is the largest-scale inquiry into politicians in about two years.

The investigations are also drawing public attention because they come after the Sewol ferry disaster, which disclosed widespread corruption in public service and the maritime industry.

The first lawmaker, Rep. Cho Hyun-ryong of the Saenuri Party, underwent questioning Wednesday on suspicions that he took 160 million won in bribes from a train parts supplier.

Prosecutors said the alleged bribery took place when Cho was head of the Korea Rail Network Authority, the state-run railway construction company, and later a member of the National Assembly’s Land, Transport and Maritime Affairs Committee.

The second lawmaker, Rep. Park Sang-eun, also of the Saenuri Party, was questioned by prosecutors Thursday. He is suspected of having received kickbacks and illegal political funds, including those from candidates the Saenuri Party nominated to run in his constituency in Incheon in the June 4 local elections.

The Park case came to the fore when his driver took 30 million won in cash from the lawmaker’s car and handed it over to authorities. Later, investigators found a huge sum of money at the home of his son.

While the cases of the two ruling party lawmakers look like typical bribery scandals involving greedy, dishonest politicians, the third case involving three lawmakers is taking shape as a more serious political scandal.

The three lawmakers, all from the main opposition New Politics Alliance for Democracy, are suspected of taking kickbacks from the head of an entertainment training school in Seoul. In return, they allegedly teamed up to revise the relevant law to allow the school to remove the Korean word for “vocational” from its name. Koreans usually associate the words vocational or professional training with low-level institutions.

Prosecutors said that the three lawmakers ― Reps. Shin Geh-ryoon, Kim Jae-yun and Shin Hak-yong ― are suspected of taking kickbacks ranging from 15 million won to 50 million won from the head of the Seoul Arts College. All three allegedly had close personal relationships with the head, former actor Kim Min-sung.

Prosecutors said the three lawmakers led the revision of the relevant law at Kim’s request. In short, they sold their constitutional right to make and revise the law.

All the three deny the allegations, although prosecutors who have been investigating the case for months say that they have secured enough evidence, including CCTV footage and testimonies, to charge them.

The NPAD has resorted to its typical political offensive, accusing the prosecution of conducting a politically-motivated investigation. Some also claim that the prosecution is targeting politicians to restore its reputation, which was damaged by its botched investigation of the family that owned the Sewol ferry.

The prosecution should not be swayed by any political maneuvers and must get to the bottom of the cases and seek due punishment. The cases show that corruption is still rampant among elected officials.