The ongoing investigation into defense acquisition programs is revealing yet more cases of dirty connections between the military and the industry.

The joint investigation team arrested former Navy Chief of Staff Jung Ok-geun on Thursday on suspicion of taking kickbacks from two affiliates of STX Group, which received orders for supplying ships and engines to the Navy when Chung held the top post.

Jung’s arrest came one day after investigators arrested his son and a former chief of naval operations surnamed Yun in the same case. They said STX had offered 770 million won to a firm run by Jung’s son, the organizer of a yachting competition during a Navy event held in 2008. Jung, who was Navy chief at the time, allegedly asked for the money through Yun, who was an outside director of STX.

As investigators suspect, it could not have been a coincidence that STX secured Navy orders for supplying engines for high-speed guided-missile patrol boats, which were worth 73.5 billion won, two months after the yachting competition.

Besides, during Jung’s tenure, STX, a latecomer in the defense industry, beat such big names as Daewoo, Hyundai Heavy and Samsung in winning contracts for building 10 of the 18 high-speed guided-missile patrol boats and supplying engines for six next-generation frigates.

This solidifies the suspicion that the money given to his son was a kickback for favors Jung might have offered STX in the Navy procurement programs. It comes as no surprise that Yun, who retired as a rear admiral in 2004, served as an outside director of STX. The two both attended the Naval Academy, with Yun graduating four years earlier than Jung.

This is a typical case of corrupt connections involving senior military officers, retired officers and industry players. What’s unnerving is that there seems to be no end to graft cases in the defense acquisition programs. Not too long ago, dozens of active and retired officers and industry officials were indicted in connection with the supply of faulty parts to the salvage ship the Tongyeong.

It is clear what needs to be done. First, the investigation team should get to the bottom of all the cases that have come up so far and mete out the heaviest possible punishments.

Relevant laws and regulations should be revised so that revolving-door employment between the military and the defense industry should be regulated in the toughest manner. In addition, punishments for defense contractors implicated in corruption should be strengthened, including suspension of their bidding rights.