South Korea’s former-president Yoon Suk Yeol has been sentenced to 30 years in prison for sending drones into North Korea, a move prosecutors argued was aimed at creating a pretext for his failed martial law declaration in 2024.

The Seoul central district court found Yoon guilty of abuse of power and aiding the enemy, saying he had conspired in the October 2024 drone incursion from the outset, the news agency said. Special prosecutors said back in April that Yoon’s effort to “fabricate wartime conditions” with the drones had undermined state security.

Yoon denied wrongdoing. His lawyers said he neither ordered nor later approved the operation, which they said was unrelated to martial law and instead a response to months of North Korean launches across the border of balloons stuffed with rubbish.

North Korea accused Seoul of flying drones over Pyongyang to drop propaganda leaflets three times in October 2024. South Korea’s defence minister at the time, Kim Yong-hyun, issued a vague denial before the defence ministry said it could neither confirm nor deny the allegations. Tensions rose sharply but it did not lead to any military clashes.

Yoon was “given 30 years in jail” for the charges, a spokesperson for the Seoul Central District Court told the AFP news agency. South Korean news agency Yonhap also reported on the sentence. Yoon, who is already in custody, can appeal Friday’s lower court ruling.

Prosecutors argued that the operation heightened tensions with North Korea and led to the leak of classified information – including details about force capabilities – after the drones crashed, Yonhap reported.

Friday’s ruling adds to a series of judgments against the ousted conservative leader, whose martial law order plunged Asia’s fourth-largest economy into its deepest political turmoil in decades.

Yoon was given life in jail in February, for leading an insurrection to “paralyse” South Korea’s National Assembly with his martial law declaration. He has appealed against the conviction, insisting that he declared martial law “solely for the sake of the nation”.

Yoon was removed from office last year after the Constitutional Court upheld his impeachment, triggering a snap election that was won by liberal President Lee Jae Myung.

Drone flights remain a flashpoint in tensions between the two Koreas, which remain technically at war.

Lee expressed regret earlier this year after an investigation found government officials had sent drones into the nuclear-armed North in January.

North Korean leader Kim Jong-un’s powerful sister called Lee’s statement “wise behaviour”, but hopes for a rapprochement faded after the diplomatically isolated nation returned to calling the South its “most hostile” enemy.

With Agence France-Presse and Reuters