A team appointed by UN Secretary-General Ban Ki-moon found that up to 40,000 civilians may have been killed during the last stage of the conflict. The team said there were credible allegations both sides committed war crimes.
The photographs will place additional pressure on British PM David Cameron to announce whether or not he will attend the Commonwealth Heads of Government meeting (CHOGM), in Sri Lanka in November.
A Downing Street official with Cameron on his visit to India said on Monday that no decision had yet been taken.
NGOs and organisations, among them the cross-party Commons Foreign Affairs Committee, have called on Cameron to boycott the Commonwealth summit in Colombo.
In March last year, the shocking video telecast on UK's Channel 4, had shown Prabhakaran's son dead with five bullet holes in his chest.
The May 18, 2009 footage of the 12-year-old was screened at the FIFDH film festival in Geneva and was later aired on Channel 4.
According to reports, the Channel 4's shocking new video is said to be a 'trophy video' shot by Sri Lankan troops which were present during the cold-blooded execution of the Prabhakaran's family.
The Sri Lankan High Commission in London had then "categorically rejected the malicious allegations" of the 60-minute documentary titled 'Sri Lanka's Killing Fields: War Crimes Unpunished'.
