The video captioned "Ruthless" claims to have recorded eyewitness accounts of LTTE's child recruitment and its violence against Tamil civilians.
"These are authentic evidence coming from Tamil civilians who had been at the receiving end", Lakshman Hulugalle, the director general of the media centre for national security told reporters.
The video contains an account by a Catholic priest in the St Mary's Church at Valayanamadam in the northern Mullaithivu district about forced recruitment of the under-aged children for military purposes by the LTTE.
The priest narrates the LTTE's alleged storming of the church premises which provided refuge to displaced children as the army was making its advance during the final stage of the military battle.
Similarly, an alleged LTTE action to blow up a bus with civilians at Mullaivaikkal, the scene of the final battle, has been highlighted.
Hulugalle said the government aimed to counter "false accounts" provided in certain international media such as the British Channel 4 TV of unsubstantiated evidence coming from unknown individuals.
"The people shown in this video are available for anyone to be interviewed", Hulugalle said.
The release came as Sri Lanka is bracing to face another session of the UN Human Rights Council sessions in Geneva later this month.
The local press speculates that US was planning to move a resolution against Sri Lanka at the sessions.