Deputy Interior Minister Hussein Kamal said that the investigation led by Deputy Prime Minister Rowsh Nuri Shaways was still underway.
An official in Shaways' office said the ministerial committee had not finished its work and needed more time.
US and Iraqi forces discovered 173 malnourished Iraqi detainees when they went into the facility in Baghdad on 13 November.
Some of the inmates showed signs of torture, US and Iraqi officials said.
A US general was so concerned with what he found that he took immediate control of the jail.
The US military has released some details about the jail.
On 15 November, Prime Minister Ibrahim al-Jaafari ordered an investigation and promised the results within two weeks.
The US Embassy touted the investigation as proof that the Iraqi government was taking action and that there was no need for an independent, international inquiry.
There have been conflicting reports about the inmates, but many were believed to be Sunni Arabs.
"We believe that the government is part of this case, so we do not expect that it would try to reveal the truth"
Spokesman, General Conference for the People of Iraq
Hundreds of Sunnis have been found dead along the Iranian border, many with gunshot wounds to the head or showing signs of torture.
Some leaders say Shia militias that have been incorporated into the Interior Ministry, which controls the police, are responsible and they have formed death squads that regularly carry out thousands of extrajudicial abductions and executions.
The failure to release any results on Thursday did not surprise Sunni politicians.
"We believe that the government is part of this case, so we do not expect that it would try to reveal the truth," said Harith al-Obaidi, a spokesman for the General Conference for the People of Iraq. "If some members in the government were not involved, the facts would have been announced in less than two-week period. It is a deliberate delay."
Muhammad al-Mishihdani, a senior official in the National Council for National Dialogue said that simple cases of torture reported in the past were never solved, so he had little expectations for this investigation, just weeks before 15 December parliamentary elections.
"We think that the government is not serious in this matter because it does not want to be dragged into controversy while the elections are looming," he said.
"We still demand an international investigation because nobody expects that the government would indict itself."
After US troops took over the jail in Baghdad, President Jalal Talabani said there was "no place for torture and persecution in the new Iraq" and that anyone involved "would be severely punished".
But since then, al-Jaafari has said the poor condition of the detainees has been exaggerated, and Interior Minister Bayn Jabr suggested that some making the torture allegations were supporting fighters or had a personal score to settle.
US President George Bush has repeatedly said that one goal of the US invasion of Iraq is to install a democratic government that respects human rights.
In a sign of the differing views on detainee abuse, America's top military man, Marine General Peter Pace, and Defence Secretary Donald Rumsfeld contradicted each other on Tuesday on the role of US troops in Iraq while speaking to reporters at the Pentagon.
Rumsfeld says US troops need
only report the abuse not stop it
Pace said US troops had a duty to intercede and stop abuse of prisoners by Iraqi security personnel, while Rumsfeld told the general he believed US soldiers only had to report the abuse, not stop it.
Pace stuck to his original statement. "If they are physically present when inhumane treatment is taking place, sir, they have an obligation to try to stop it," Pace told his civilian boss.
The unusual exchange occurred during a discussion at a news conference about the relationship between US forces in Iraq and an Iraqi government considered sovereign by the United States.