THE NSW Supreme Court has ruled Cr Katie Milne and billionaire developer Bob Ell must each pay their own costs in the defamation case that was awarded against the Tweed Greens councillor.

On March 7, Cr Milne was ordered by Judge McCallum to pay the founder and executive chairman of the Tweed's biggest developers, Leda, $15,000 in damages.

At a hearing to determine costs on April 11, Judge McCallum again emphasised Mr Ell took the unusual step of not giving evidence in court to the hurt his reputation had suffered due to Cr Milne's allegations and she ordered both parties pay their own costs.

But the Daily News understands it still leaves Cr Milne with a legal bill estimated to be at least $50,000 that was awarded against her in interim arguments during the same case.

However, it could take a year before the costs are independently assessed and will be enforced.

The next council election is scheduled for March 2015.

If forced to declare bankruptcy, Cr Milne would be ineligible to remain a councillor under the Local Government Act.

The defamation action stemmed from a letter to the editor written by Cr Milne in which the court ruled she unfairly linked Mr Ell to murdered Sydney standover man Michael McGurk and made references to Mr Ell's political donations. The judge said the imputations made against Mr Ell were serious but Cr Milne's letter was not written in malice.