The complex was found in the Vellamullavaikkal sub-post office by the troops as they moved further in, the defence ministry said.
"The house with a wide sitting room, plus three spacious rooms was protected closely by bunkers on the orders of the LTTE supremo V Prabhakaran," the ministry said, quoting it the escapees as saying.
"All anti-LTTE men and women had been kept imprisoned and tightly tethered to heavy metal chains, generally used for elephants," it said.
Those metal prison cages of about 10-12 ft in height have been designed for padlocking, and another portion of the chamber appeared to have been used for beating and torturing, the ministry said.
"Unconfirmed reports said that Prabhakaran himself watched his enemies under punishment. Walls around that portion have been splashed with blood stains and pieces of hair of those who would have been subjected to LTTE torture," the ministry said.
Above one of those metal cells was a spread barbed- wire that ran until up to the roof of the house, it said.
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