Pathmanathan, better known as 'KP' or Kumaran Pathmanathan, was flown to Colombo on Thursday night following his arrest in Bangkok, the Thai capital, the Island newspaper reported on Friday.
Selvarasa Pathmanathan, an alleged arms smuggler who is the new Liberation Tigers of Tamil Elam chief, was arrested on Thursday night from Thailand, reports said.
LTTE's head of International relations Selvarasa Pathmanathan told BBC that their 'incomparable leader had attained martyrdom'.