The High Court has ruled that the former assistant Dublin City and County manager, George Redmond can proceed with an action for costs against the Mahon Tribunal.

However, the court ruled that he cannot proceed with a challenge to the findings of the tribunal that he engaged in corruption and obstructed and hindered the inquiry, because of what the court called inordinate and inexcusable delay in pursuing the action.

The tribunal had sought to have both challenges dismissed on the grounds of delay.

However, Mr Justice Paul Gilligan ruled the balance of justice demanded that Mr Redmond's action challenging the tribunal's decision to refuse him his costs, should proceed.

In relation to Mr Redmond's challenge to the tribunal's findings against him, the judge said the then tribunal Chairman, Mr Justice Fergus Flood is long since retired.

He said the issue of the redaction of parts of James Gogarty's evidence and its suppression raises issues as to why it was done and why the nature of the material was never divulged until a short time before another challenge to the tribunal in the High Court.

Mr Justice Gilligan said this was a situation of serious concern.

But he said it was now 12 years since the conclusion of public hearings involving Mr Gogarty.

He said Mr Redmond had effectively done nothing over a period of more than six years from April 2005.

He said the lapse of time was simply too great.

He said the delay involved since the publication of the second and third interim reports by Mr Justice Flood gave rise to a substantial risk that it was now not possible to have a fair trial within a reasonable period of time on the challenge to the substantive findings.