Police spokesman and Superintendent Ajith Rohana's office issued a picture of K P Selvanayagam alias Gobi.
He was described as a 31 years old, 6 feet tall and fair in complexion.
The police also provided a hotline number for information on his whereabouts.
In Geneva, during the ongoing 25th session of the UN Human Rights Council, Sri Lanka in a written response said that Gobi was involved in reviving the LTTE.
"Investigations revealed that K P Selvanayagam aka Gobi who had been overseas and returned to Sri Lanka was actively involved in reviving the LTTE through regrouping LTTE cadres and recruiting unemployed local youth with the intention of using them for acts of terrorism," it said.
On the charge of making contact with Gobi, Sri Lanka arrested and later released two frontline human rights activists.
The arrests drew sharp international condemnation from the US, the UK and Amnesty International.