http://www.hinduonnet.com/thehindu/mp/2 ... 580400.htm

Sri V. Dakshinamoorthy is a great music composer in Malayalam film world.

Anyone out there has heard Swami's singing?

Sri VD had composed music for Tamil Film world. These include "Nanda Ni En Nila" in Madhuvanti and "Endha Paadhai Engae Payanam" in Sindhubhairavi sung by SPB and KJY respectively. I think he also composed music for Swami Ayyappan, yet another movie.

All these days I never knew that he would perform in traditional carnatic platform.

Kaumaaram

he used to sing regulary at the Vaikom siva temple if I am not mistaken.

He is better known as a Music Director (usually dabbles with Carnatic Music in films), but he does give Carnatic Music vocal concerts every now and then, mainly in Kerala.

Dakshinamurthy or better known as swamy, is a great music composer.1960-80 is the golden era of Malayalam film music.Swamy,G.Devarajan,Baburaj,M.B.Sreenivasan, they produced plenty of melodious songs.
Swamy is highly knowledgeable in carnatic,he used to give concerts,not only at Vaikom temple(he gives credit to vaikathappan for all achievements he got),but other places also,I have attened his concert at Shastry hall,Chennai.
But surely,he was a better composer than a platform singer
Most of his songs are raga based and he used sankarabharanam,kharaharapriya to lighter ragas like madhuvanthi meticulously.
His songs may be analysed at light classical thread.

if you mean the malayalam movie which later dubbed to tamil, the music is by late Devarajan.Incidenatlly,that film contains some wonderful songs, sabarimalayil thanka suryodayam(sung by Yesudas) sabarimalayil vanna(by TMS in tamil) based on ananda bhairavi.