The North's ruler said something to Kim with his finger pointing to the former minister of state security, the footage showed.

But he skipped a handshake with Kim, though the ex-spy chief made a military salute in a possible indication that Kim Jong-un may still harbor ill feelings about him.

Seoul's unification ministry said in February that Kim, 72, was fired in mid-January following a probe by the ruling party into the spy agency.

He was fired over suspicions that the intelligence agency committed wrongdoing including human rights violations, abuse of power and corruption, it said. An unidentified number of the spy agency's officials were executed.

But he appeared at the military parade, wearing the badge of a general, in a possible sign that he may have been reinstated. Kim's military rank was demoted to major general due to the reported dismissal.

North Korea's security ministry has powerful authority as it screens so-called reactionary elements in society, supervises political prisoners' camps and arrests those who attempt to flee the country.

Known as a close aide to the North's leader, Kim became the head of the spy agency in April 2012 after Kim Jong-un took office in late 2011.

He is also known to have spearheaded the move to execute Jang Song-thaek in December 2013, the once-powerful uncle of the North's young leader.

Nam Sung-wook, a professor at Korea University, said that Kim Jong-un's avoidance of the handshake appears to be a warning message not to behave rashly.

"The former spy chief may have difficulty in fully restoring his power even if he has been reinstated," he added.

The Ministry of Unification said that it is not certain whether Kim may have been reinstated as he was not spotted at other major events related to Kim Il-sung's birthday. (Yonhap)