SENATOR Ivor Callely will be due a back-payment in tax-free expenses of at least €12,000 after winning his High Court case against the Seanad.

Callely's day-to-day expenses have been suspended since April and are listed on Dáil records as "ceased pending investigation".

The High Court found on Friday that the senator had been treated unfairly after being suspended by his peers amid controversy over travel claims in connection to a holiday home in Co Cork.

Callely has not been allowed to claim any expenses under a new system of allowances introduced by finance minister Brian Lenihan last March.

The embattled senator is entitled to a minimum payment of €1,354.16 for every month between April and December, the Sunday Tribune has learned.

If he elects to claim the lower guaranteed unvouched payment, Callely will be in line for a windfall payment of at least €12,187. He could also decide to vouch for his expenses and, if he did that, could be entitled to as much as €16,499 tax-free, the maximum allowable claim for a Dublin-based senator.

A Seanad source said: "It will not be possible to withhold these payments any longer in view of the High Court action as it could leave us on very shaky ground."

Callely may also be entitled to a refund of salary withheld from him during the period of his 20-day suspension last year. On the basis of his basic €65,621 salary scale, that would mean another back-payment from the Dáil of at least €3,595 in wages.

It is understood that Callely is already considering further legal action against his political colleagues following the successful High Court challenge.

The investigation into him was sparked by more than €80,000 in travel claims in connection to his holiday home in Kilcrohane, Co Cork.

Later inquiries revealed that the senator had also double-claimed on his expenses while a minister and put in for mobile-phone costs from a company that no longer traded.

A Seanad committee ruled last July that Callely had intentionally misrepresented his normal place of residence and handed down a 20-day suspension.

It is understood the Houses of the Oireachtas and the Seanad Committee will consider a plan of action this Wednesday at a meeting. An expensive Supreme Court challenge is being considered, which will only add further costs for the taxpayer.