Lord Justice Goldring said the jury at the inquests into the deaths of 96 Liverpool fans will have to consider whether the changes were ordered to deflect criticism or blame fans.
The disaster took place in April 1989 during an FA Cup semi-final.
The coroner added none of the 96 should be blamed for their deaths.
As he set out some of the topics which will arise during the hearing, he asked the jury to consider the "conduct of the fans, or some of them, excluding those who died".
Lord Justice Goldring added: "I phrase it in that way because I don't believe anyone will suggest that the conduct of those who died in any way contributed to their deaths."
Lord Justice Goldring set out "some of the issues that may arise" during the inquests, including:
The jury was told senior ranks and lawyers at South Yorkshire Police reviewed all self-taken statements by officers present at the disaster and amended some of them before forwarding them on to West Midlands Police, who were investigating the events.
The coroner said since the disaster it had become known that statements had been amended, with the changes "varying in type and significance".
Lord Justice Goldring said: "Some simply involve corrections of language and factual error. Others involve removing expletives.
"A number involved the removal of comments criticising the police leadership on the day of the disaster. A small number were amended to remove comments which were critical or even abusive of the fans at the match."
He added some comments about "poor and defective radio communications" were also removed or changed.
The coroner told the jury they would have to consider whether the amendments affect their view of the "reliability" of early written statements given by the officers.
He added they would have to ask why they were amended, if it was an "innocent" alteration or "part of a policy of blaming fans in order to deflect criticism from the police".
The jury, consisting of seven women and four men, were also told about previous inquests in 1990.
Lord Justice Goldring said: "The hearings were brief, few questions were asked of the witnesses, the bereaved families and their representatives were not given disclosure of the source documents in advance."
The inquest heard the coroner in the previous hearings took the decision that all of the victims were beyond help after 15:15.
On this point, the jury at the fresh inquests were told: "From the start this was a highly controversial decision which many of the bereaved families very strongly disputed. We shall not follow that course."
The coroner has concluded his opening statements, with the hearing due to continue on Thursday.
Police accounts of the Hillsborough disaster were amended to remove negative comments about senior officers, a coroner has said.