Poland's government said Tuesday it has closed its investigation into allegations that the country may have hosted secret CIA prisons.

Government spokesman Konrad Ciesiolkiewicz would not comment on any findings made by the probe, which Prime Minister Kazimierz Marcinkiewicz ordered in early December.

"The case was closed last week," Ciesiolkiewicz said.

He said Zbigniew Wassermann, the minister in charge of intelligence services, coordinated the investigation.

Wassermann's report was delivered to a parliamentary commission in a closed-door session last week. Members of the panel declared themselves fully satisfied and decided to drop any further investigation.

The spokesman said the government does not plan a separate announcement of the findings.

Allegations that the CIA may secretly have held terror suspects on Polish territory were raised by New York-based Human Rights Watch. Polish officials have denied them vehemently.