A member of the banking inquiry has proposed that businessman Denis O'Brien be called as a witness, RTÉ News had learned.

Sources close to the inquiry say that Fianna Fáil's finance spokesman Michael McGrath raised the prospect of calling Mr O'Brien as a witness earlier this week.

When contacted, Mr McGrath confirmed he had written to the inquiry and said the issue would be considered next week.

"As a large commercial borrower from the Irish banks who has publicly expressed views about the manner in which borrowers were dealt with, Denis O'Brien may be in a position to give valuable evidence to the banking inquiry," Mr McGrath stated.

"In addition, his experience as a former Deputy Governor of Bank of Ireland and as someone with significant media interests, Mr O'Brien may be in a position make an important contribution on several aspects of the terms of reference being examined by the Inquiry," he stated.

"The committee is due to hear from a number of property developers but it is important that other commercial borrowers are also heard. Ultimately it is a matter for committee to decide but I believe the work of the banking inquiry would be enhanced if Mr O'Brien were to give evidence before it," he added.

Mr McGrath added that as the matter is due to come before the inquiry next week, it would not be appropriate for him to comment further.