Attorney-General George Brandis was personally involved in the Bell Group matter one month earlier than he claims he was, the ABC has been told.

Key points: George Brandis may have been involved in Bell Group matter earlier than previously claimed

George Brandis may have been involved in Bell Group matter earlier than previously claimed Senator Brandis told Senate he first became involved in Bell case on March 3, 2016

Senator Brandis told Senate he first became involved in Bell case on March 3, 2016 7.30 has been told Senator Brandis spoke to WA Attorney-General about Bell on February 1, 2016

If the claim is true, Senator Brandis may have misled Parliament over the issue.

7.30 has been told Senator Brandis spoke to West Australian Attorney-General Michael Mischin about the case in early February last year — a full month before Senator Brandis said he first became personally involved.

Senator Brandis said he could not recall the conversation.

"I have no recollection or record of any telephone conversation with Mr Mischin on or about 1 February 2016," Senator Brandis told 7.30 in a statement.

But 7.30 has been told Senator Brandis informed Mr Mischin he had had a briefing on the Bell matter ahead of a hearing in the High Court set down for the following week.

It was asserted that Senator Brandis told Mr Mischin that while he understood there was a potential dispute, he had not made a final decision on whether the Commonwealth would intervene.

Shadow Attorney-General Mark Dreyfus described the revelations as "extraordinary".

Mr Dreyfus told the ABC any other prime minister would demand "a proper and full explanation".

What is the Bell Group case?

WA businessman Alan Bond, who died in 2015. ( Reuters: Mark Baker )

Alan Bond's Bell Group collapsed spectacularly in the 1990s, and 20 years on the tussle over its assets continues.

It is the longest running, most expensive litigation in Australian history.

The WA Government, impatient to have the litigation settled, passed legislation in late 2015 to seize control of the Bell liquidation — potentially jumping ahead of other creditors, including the Australian Tax Office (ATO).

WA thought it had the backing of the Federal Government after a secret deal brokered with then-treasurer Joe Hockey.

But the ATO pursued a High Court challenge, belatedly joined by the Commonwealth Government.

The challenge was successful, with the High Court unanimously ruling in May last year that WA's so-called Bell Act was unconstitutional.

The person who argued the case in court was then-solicitor-general Justin Gleeson, and the matter was at the heart of his bust-up with the Attorney-General, which saw Senator Brandis issue an extraordinary directive restricting access to Mr Gleeson.

What do we know about Brandis' personal involvement?

Former Solicitor-General Justin Gleeson clashed with Attorney-General George Brandis. ( ABC: Luke Stephenson )

Senator Brandis initially did not want the Commonwealth to intervene in the High Court challenge, against the strong advice of his department and Mr Gleeson.

When Senator Brandis was accused of seeking to protect a sweetheart deal with WA, the Attorney-General was forced to explain what he knew about it and when.

"The first personal involvement I recall having in the matter was on 3 March this year, although my office had been dealing with the matter prior to that time," Senator Brandis said in a statement to the Senate on November 28.

Senator Brandis was asked what he meant by "personal involvement" by Senator Murray Watt during Senate estimates last year.

"I had no personal involvement in the matter before. I was aware of it, because it was a matter of public record that this Bell litigation was happening," Senator Brandis said.

"I imagine that I first became aware of it when you first became aware of it, Senator Watt, because we both read the newspapers, and it was a matter that was in the newspapers in late 2015."

Did Senator Brandis attempt to stop the ATO challenging the WA legislation?

7.30 has been told the Attorney-General and his office explored the option of issuing a legal services direction prohibiting the ATO from intervening in the High Court.

Senator Brandis said he could not confirm these matters.

"The questions go to the content of legal advice. It is the long standing practice of successive Australian governments not to disclose legal advice," he said in a statement.

In any case, he said "no such direction was ever issued".

"In fact the Commonwealth supported the ATO's position."