Fisheries official Lee Dae-jun was reportedly fatally shot in 2020 by North Korean soldiers near the de facto maritime border and his body later burned by Pyongyang.

His killing became a political flashpoint, with ex-president Moon Jae-in’s administration accused of mishandling the probe to curry favour with North Korea.

Moon’s national security chief, Suh Hoon, was arrested and accused of ordering intelligence reports destroyed to conceal the murder near the inter-Korean sea border.

Suh was also accused of manipulating evidence to support Seoul’s controversial claim that the late fisheries official had sought to defect to the North.

Other top security officials under Moon — including ex-spy agency chief Park Jie-won and former defense minister Suh Wook — were indicted on similar charges.

But the Seoul Central District Court acquitted all three officials, citing insufficient evidence.

Based on what prosecutors submitted, there was not enough to “establish that there was an attempt to frame the incident as a defection to North Korea”, the court determined.

An initial probe by the coast guard suggested Lee had tried to defect to the North over family problems and debts from gambling.

But Lee’s brother insisted Lee would never have chosen a life in North Korea.

The dovish Moon administration’s handling of the 2020 case was heavily criticised by his successor, the more hawkish Yoon Suk Yeol.

Yoon was ousted in April and is now in prison following a brief but disastrous imposition of martial law.