State television channel ITN speculated over whether Mahela Jayawardene and Thilan Samaraweera may have "changed the game" by getting out cheaply.
The station added a local businessman had placed an ,000 bet on Sri Lanka losing the game.
Sri Lanka, who are one of the favourites to win the tournament, fell short of Pakistan's total of 277-7 by 11 runs on Saturday, leaving thousands at a packed R.
Premadasa stadium in Colombo devastated.
"It is with deep regret that we note that a leading television channel in a special programme, namely 'Wimasuma', has stated that Sri Lanka has lost against Pakistan due to two of our leading players not getting runs in that game," Sri Lanka Cricket said in a statement.
"Further, they added that the two players had failed intentionally, thereby implying that our players might have been involved in match-fixing," said SLC.
"SLC strongly condemns the bona fides (sic) of this anchor who hosted the programme carrying a story that is baseless