Edits made to the Hillsborough disaster page on Wikipedia have been described as an "absolute insult to victims and their families".
Margaret Aspinall, mother of one of the victims said: "It's an absolute insult to the families who are fighting for where we are today and it has to be investigated".
Sheila Coleman from the Hillsborough Justice Campaign added that the distress was compounded by the timing of the revelations.
"That this happens now when the families are immersed in the inquest procedure goes to the heart of why should they trust the establishment," she said.
The police watchdog - The Independent Police Complaints Commission - say they have identified a total of 13 individuals - 12 former and one serving police officer - as suspects in their investigation into the Hillsborough disaster.
The suspected offences include manslaughter, perverting the course of justice, and misconduct in a public office. Four of those identified are also of interest to the criminal inquiry into the disaster, the IPCC said.
Margaret Aspinall, chairwoman of the Hillsborough Families Support Group, who lost her 18-year-old son James in the disaster, has said the publication of the documents would uncover more detail about what happened.
"We want the legal system to acknowledge what happened beyond 3.15pm," she said.
"They did not all die by 3.15pm or sustain all the injuries that would have killed them by 3.15pm.
"They did all not die in an accident and it's absolutely ludicrous to suggest that."
A report explaining the contents of the documents will be published this week by the Hillsborough Independent Panel, which has been overseeing the release.
The 96 Liverpool supporters died in a crush at Sheffield Wednesday's Hillsborough stadium on April 15, 1989 where their team were to meet Nottingham Forest in an FA Cup semi-final.
A report into the disaster by Lord Justice Taylor, published in 1990, found that the main reason for the disaster was a failure of "police control".
The victims' families say it is an injustice that no individual or organisation has been held fully accountable for the disaster.
Thousands of official documents relating to the Hillsborough disaster will be published for the first time this week.
The papers, some of which had been covered by the 30-year rule, come from the files of 80 organisations including the Government, South Yorkshire Police, Sheffield City Council, the South Yorkshire coroner and the fire and ambulance services.
The families of the 96 football fans who died in Britain's deadliest sporting disaster will have the first access to more than 400,000 pages on Wednesday morning.
Later that day a statement is expected to be made to MPs in the House of Commons.