The criticism from the women came in an opinion piece published by newspaper Aftenposten.
In the article, the three women wrote that they were unprepared for the intense media focus on them after the complaints against Giske became public.
"Media pressure constituted a heavy extra burden during a time that was already very demanding. It became clear that there was a battle going on over the telling of the story, and some individuals were prepared to resort to anything," the three write.
The Aftenposten article is written anonymously. The newspaper states that it knows the identity of the authors.
According to the authors, one of the whistleblowers was contacted by a newspaper shortly after Giske had been informed of their stories and identities. All three were later contacted by journalists who had gained information regarding their identities.
"One journalist called an employee in the Labour Party and gave them two of our names. One called a family member. One told one whistleblower the identity of another whistleblower. One called party colleagues and asked whether they knew the content of one the reports we had made," the opinion piece reads.
The three encouraged media through the article to be aware of "how far they will go in the hunt for new headlines".
"If the public has the right to know all the details in cases like these, the abuse of positions of power will be easily be able to continue, because the burden of taking a stand will be too great," they wrote.
Alexandra Beverfjord, news editor with national broadcaster NRK, said she understood why the three women felt pressure from the media had been excessive.
"We make thorough ethical considerations before every single broadcast. This is a demanding topic, but it is a topic that has had a lot of attention over a long period. I understand the media focus they are experiencing, but we must both be considerate towards those raising reports and act correctly towards those claims are being made against," Beverfjord said to NRK.
The editor added that NRK denies having any part in causing the identities of whistleblowers to be made known to others.