In a near mirror image of last week's publication of the Chilcot report in the United Kingdom, after which former British PM Tony Blair came in for strong criticism, the Danish document will be blocked from public access, leaving Rasmussen shielded from similar scrutiny.
After the publication of the Chilcot report, a large quantity of information, including records of communications between Blair and former U.S. President George W. Bush, has been made available for public download.
But a 14 year-old document written by Rasmussen in the lead-up to the U.S.-led invasion of Iraq in 2003 will not be released into the public domain, the Danish parliament's ombudsman confirmed to Jyllands-Posten.
The ombudsman statement says that publication of the Danish material is not in the national interest, since it is potentially damaging to other countries.
The controversial 2013 Freedom of Information Law (Offentlighedsloven) enables parliament to keep public records inaccessible to parties with 'no part' in the cases in question. It is a clause in this law that has enabled the ombudsman to keep the Rasmussen document classified.
The note in question relates to a meeting between Rasmussen and then U.S. Deputy Secretary of Defense Paul Wolfowitz in 2002, reports Jyllands-Posten. While the exact contents of the document are unclear, Politiken has previously claimed that Rasmussen stated Denmark would "without a doubt" offer its support in the campaign to oust former Iraqi dictator Saddam Hussein.
Denmark's government later gave its approval to the country's participation in the 2003 war.
A number of opposition politicians have now called for the document to be made public, despite the ombudsman having blocked the move.
"It is regrettable and once again casts doubt over whether we know everything regarding this case," defence spokesperson Eva Flyvholm of the Red-Green Alliance (Enhedslisten) party told Jyllands-Posten.
Marie Krarup of the Danish People's Party told the newspaper that the document should be put towards a parliament committee, which could then assess its suitability for publication.
"I support transparancy in principle. But there are sometimes cases in which this is not possible due to the relationship between foreign powers and state security. The document could contain information regarding Denmark's security, which could be used against us," Krarup said.
In 2015, Prime Minister Lars Løkke Rasmussen controversially cancelled a government inquiry into the Iraq war shortly after taking office.
Note: This story was updated on July 22nd to correct a translation error.