The minister also added the MEPs, who came to Lithuania for a three-day visit, also acknowledge that Lithuania carried out an in-depth investigation and was the first in Europe to do so.
"I am absolutely convinced that, at the political level, everything has been done. I mean the parliamentary commission, the conclusions made and the decisions approved," Šimašius told BNS after the meeting.
"I am convinced the Prosecutor General's Office has done everything in its power investigating those incidents. It's no secret that our American partners' policy not to disclose any information related to the discussed activity was one of the limitations in this case," the minister said.
Members of the EP's Committee on Civil Liberties, Justice and Home Affairs came to Lithuania on Wednesday and have already met with Deputy Prosecutor General Darius Raulušaitis who assured MEPs the pre-trial investigation found that no people had been illegally detained in Lithuania.
During a parliamentary investigation in late 2009, two locations were identified in Vilnius and near the Lithuanian capital where premises might have been equipped for the detention of prisoners. The parliamentary probe also showed that CIA-related planes entered Lithuania's airspace in 2003-2006 several times. The investigations failed, however, to identify if any suspected terrorists were actually brought to Lithuania.
Following the parliamentary investigation, Lithuanian prosecutors opened a separate investigation but terminated the probe last January.
"Based on the data we have, there are no facts that someone was really held in these locations. It means that Lithuania can neither confirm nor deny that such incidents did or did not take place," Šimašius told BNS.
According to the minister, the MEPs' visit to Lithuania might have been prompted by the lack of information on what has been done following the parliamentary probe.
"There are certain psychological reasons why the parliamentarians came to Lithuania. Following the parliamentary investigation three years ago, they lack information on what has been done afterwards," the minister said.
"For my part, I informed them that following that investigation, Lithuania has made systematic changes, has made conclusions, and what was happening several years ago should not happen again," Šimašius said.
United States denied information
Lithuania has done everything it can investigating reports about an alleged CIA prison in Lithuania, and the investigation was impeded by the United States' refusal to share information, Lithuanian President Dalia Grybauskaitė said on Thursday.
"Lithuania is one of the most open countries whose politicians have done everything they can. And the legal investigation, no doubt, stalled due to the fact that we did not receive additional information from the United States," the president told journalists on Thursday.
"What concerns prosecutors and other investigators, our investigation stalled as we had no access to full information due to the other country's refusal to provide it," Grybauskaitė said
The Lithuanian president believes the MEPs will appreciate Lithuania's efforts in looking for the truth.
"I believe Lithuania will be rated pretty positively as we were one of the first countries that dared to speak openly about its own problems, and that will be appreciated," the Lithuanian president said.
Later on Thursday, the delegation is scheduled to visit the State Security Department's base in Antaviliai near Vilnius where, according to media reports, a secret detention center was located.