Sri Lanka's [Images] top Tamil Tiger leader Velupillai Prabhakaran on Friday described his chief peace negotiator Anton Balasingham, who died in London [Images] on Thursday, as his best friend and source of energy while conferring upon him a posthumous title.

Balasingham, 68, died of bile duct cancer and his funeral is due to be conducted in London.

"A source of unwavering strength in the political and diplomatic efforts of our freedom movement, and the light of our nation is extinguished," Prabhakaran, 52, said.

"His death comes at a time when we needed him most, as our freedom struggle intensifies. I cannot find words to express my grief and loss," Prabhakaran said, suggesting that there could be an intensification of conflict.

Balasingham first met Prabhakaran in Tamil Nadu in the late 1970s and since then they had been close associates.

"From the beginning of our struggle, when we first met, there was a deep mutual understanding. The fondness that rose from that understanding developed into a rare friendship. We thought and acted in unison. Our friendship grew in strength through our shared day-to-day experiences. This friendship stands apart from ordinary human relationships. It matured with time and was shaped by our shared history," Prabhakaran said.