Roshan Ranasinghe, who was sacked as the sports minister, fears he was poisoned while leaving on an overseas tour about 1 ½ months ago.
Ranasinghe said he left as a healthy person, but landed in Japan very sick.
Medical tests found a certain chemical had entered his body.
The ex-minister said in Ampara that he believed certain powerful and corrupt persons were behind it.
He vowed to fight against corruption and fraud, saying his main policy was eliminating such ills.
He plans to contest at the next presidential polls.
