There is concern from within both major parties that Hansard, the official record of Parliament, is being substantially altered.

Liberal Senator Bill Heffernan said he had "reams of examples" of "whole paragraphs of Hansard being changed".

After hearing Senator Heffernan's remarks, Federal Labor frontbencher Joe Fitzgibbon questioned the integrity of the system.

"If the system is breaking down to the extent that it's allowing people to make substantial changes to their Hansard after the event then that needs to be addressed and I'll be raising those issues with the Speaker this week," he said.

Mr Fitzgibbon has been pursuing the issue following erroneous comments Agriculture Minister Barnaby Joyce made in the House of Representatives about drought support last year.

Mr Joyce corrected the record in the chamber that day, but it was later revealed that the Hansard record of the original remarks had also been changed.

The Minister blamed a staffer, who he said had been "counselled".

Mr Joyce says Mr Fitzgibbon is paranoid.

"[A] mistake was made in my office, it was corrected, it's been investigated by the Senate, investigated by the Speaker of the House, investigated in a special Senate committee," Mr Joyce said.

Senator Heffernan revealed his concerns about widespread changes to Hansard in a Senate committee earlier this month.

"I have taken the trouble to understand changes to Hansard," he said.

"I have reams of examples in the last three weeks, which — and this may be a wake up call to everyone — includes whole paragraphs of Hansard being changed."

According to the House of Representatives Practice, although MPs have the right to correct their remarks, changes "which alter the sense of words used in debate or introduce new matter are not admissible".

It goes on to say: "In some instances of error or inaccuracy in the Hansard reports, the position is better clarified by a personal explanation."

It also says while only the House itself can exercise control over the content of Hansard, in practice the responsibility has been transferred to the Speaker.

Similar rules exist in the Senate.