"North Korea replaced almost all of its troops, if not all, at the Joint Security Area for their failure to prevent the defection," said Kim Young-woo, chairman of the National Assembly's defense committee. "It was obviously a part of punishment for failing their mission to deter the North Korean soldier's escape. North Korea has always punished those responsible for similar failures."
Earlier, both the South Korean military and US forces in Korea told CNN they could not confirm Kim's statement. The status of the soldiers is unclear.
The change comes as the North Korean People's Army sought to prevent other soldiers from defecting by planting trees and apparently digging a trench at a section of the demilitarized zone, according to the chargé d'affaires at the US Embassy in Seoul.
Marc Knapper, the highest-ranking official at the US Embassy, tweeted a photo this week showing North Korean soldiers supervising what appears to be the planting of two trees and the digging of a trench where the North Korean soldier dashed across the border November 13.
"(T)he North Koreans have planted two trees and are digging a trench at the spot where their soldier crossed the MDL," Knapper tweeted Wednesday, referring to the Joint Security Area at the heavily fortified demilitarized zone that divides North and South Korea.
A photo tweeted by Knapper the next day showed several men, surrounded by North Korean soldiers, appearing to dig the trench behind a pair of trees.
"I'm certain that's the same spot where the soldier defected," Kim said. "North Koreans appear to be digging a trench in an attempt to prevent others soldiers from defecting to South Korea."
Dramatic video of the North Korean soldier's daring dash to freedom while being fired upon by his former comrades was released by the United Nations Command on Wednesday.
After the defector's vehicle got stuck in a gutter close to the border, he jumped out and ran toward the South Korean side, according to an official at a South Korean Ministry of Defense press briefing on Tuesday.
The 24-year-old soldier, surnamed Oh, has regained consciousness after being shot and was undergoing treatment, according to the hospital where he was taken.
Oh, whose rank has not been revealed, is the third member of the North Korean armed forces to defect this year.
More than 40 bullets were fired at him from pistols and an AK-47, South Korea's military said last week. South Korean troops did not return fire.
Oh had lost more than 50% of his blood by the time he arrived by air at Ajou University Hospital, his surgeon Lee Cook-jong told reporters Wednesday.
Lee said it was difficult to tell exactly how many times he was shot. Four major wounds were found, but he could have been shot twice in the same location.
Oh underwent multiple surgeries and doctors found dozens of parasitic worms -- some as long as 27 centimeters (about 11 inches) -- in his ruptured intestines, which may be reflective of poor nutrition and hygiene in North Korea's military.