A government statement said the countries in a joint statement had termed the UN Human Rights Council (UNHRC) resolution passed last March as an intrusive mandate and unwarranted in the context of Sri Lanka's own local investigation.
The like minded group chaired by Egypt included Algeria, Angola, Bangladesh, Belarus, Bolivia, China, Cuba, Ecuador, Indonesia, Iran, North Korea, Myanmar, Nicaragua, Pakistan, Russia, South Sudan, Sudan, Uganda, Venezuela and Zimbabwe.
This support was in addition to the concerns raised by India as Sri Lanka's all important giant neighbour had questioned the methodology of the investigation.
India backed the US-sponsored 2012 and 2013 UNHRC resolutions which pinned Colombo to a credible process of reconciliation with the Tamil minority.
However, India much to the delight of Sri Lanka abstained at the crucial vote last March which mandated an international investigation.
Sri Lanka's opposition is based on its reliance to deliver reconciliation and justice through its own mechanism.
Colombo dubs the UN investigation as one which impedes its sovereignty.
The UNHRC resolution had alleged war crimes blamed on both government troops and LTTE rebels during the final phase of the three-decade civil war.
