Velupillai Prabhakaran, or Thambi, met with an elite squad of suicide bombers prior to the March 22 attack. A Sri Lankan defense officials said 10 sailors listed as missing from the attack are "presumed dead," the Press Trust of India reported.
Thambi is the leader of the Liberation Tigers of Tamil Eelam, or Tamil Tigers, a rebel group seeking an independent state in part of Sri Lanka
A Web site supporting the Tamil Tigers, Tamilnet, said the squad met with Thambi and had their photos taken with him prior to their operation.
A Sri Lankan patrol boat radioed a distress signal after the explosion and respondents rescued six of the 16 crew members.
The Sri Lankan navy initially said a mine caused the blast and noted they didn't encounter operatives of the Tamil Tigers in the area at the time of the explosion.