The 7-day journey by Davis and an aide last year was said to have been funded by the Tamil Tigers, a group the U.S. government designated as a terrorist organization, the Tribune said.
The trip came under scrutiny after 11 supporters of the organization were arrested in an alleged conspiracy to aid the terrorist group through money laundering, arms procurement and bribery.
Davis, a five-term congressman, said he thought the trip was paid for by a Tamil cultural organization, the Federation of Tamil Sangams of North America, based in Hickory Hills, Ill.
During the visit, Davis said he spent most of his time in a region controlled by the Tigers, a separatist group seeking an independent state for 3.2 million ethnic Tamils in Sri Lanka.
Texas principal bans speaking Spanish, stirs controversy
Theater accidentally screens 'Nymphomaniac' trailer instead of Disney's 'Frozen'