A conflict between Samsung Electronics and LG Electronics is escalating.
The row was triggered last week by alleged vandalism by LG executives on Samsung's washers during an industry fair in Berlin, Germany earlier this month.
In a new twist, the prosecution said it is investigating allegations that former LG executives pocketed Samsung's confidential air-conditioner business plan related to a government-run project.
The Seoul Central District Prosecutors' Office said Monday it has started an investigation into allegations that several LG Electronics executives stole the company's business plan, which was submitted to the Korea Institute of Energy Technology Evaluation and Planning (KETEP) in 2009.
The KETEP invited public and private companies for projects to jointly develop energy-saving air-conditioner projects.
Three former executives of LG Electronics are under investigation on suspicion of stealing the Samsung documents during the selection process.
The allegation was disclosed by a former executive of system air-conditioner division at LG, surnamed Yoon, in prison for malpractices since last year. Yoon insisted he stole the Samsung business plan, and that two other executives colluded in the process.
An LG spokesman, however, dismissed Yoon's allegations.
"Yoon must not have positive feelings toward the company, as he has been behind bars for negligence of duty and other charges," the spokesman said.
The spokesman noted it is just Yoon's claim, and the company will just wait for the results of the investigation.
Meanwhile, the fresh allegation is expected to deepen the conflict between the nation's two tech giants, Samsung filed a complaints last week with the prosecution to investigate several LG executives for allegedly damaging five Samsung washing machines in Berlin ahead of the 2014 IFA electronics show.
LG's head of home appliances Jo Seong-jin is one of the executives being investigated, and the prosecutors' office has started looking into the allegations.
Samsung insisted the LG executives "deliberately" destroyed the company's premium washing machines displayed at retail stores in Berlin.
The company said personnel at the Europacenter in Berlin called the police after a man broke the doors of two of the company's washing machines, and it also secured the CCTV footage of Jo pushing the door hinges of the washing machines strongly several times on purpose in the Stegliz shop.