A judge has warned current and former members of the Church of Scientology to "sit down and be reasonable" with each other if they want to avoid a massive legal costs bill.

Scientologists Zabrina Collins and Michael O'Donnell have won High Court orders restraining former members Peter Griffiths and John McGhee from harassing, assaulting or intimidating them over work they do for their church.

Mr Griffiths, of Teeling Street, Ballina, Co Mayo, in turn has sued Ms Collins, the daughter of wrongly convicted Co Donegal publican Frank Shortt, for alleged defamation of character.

Ms Collins' address was given as Parnell Square West, Dublin.

Mr McGhee, of Armstrong Grove, Clara, Co Offaly, and Mr Griffiths, through his barrister Seamas O'Tuathail SC, gave undertakings they would not interfere with Ms Collins or her fellow Scientologist Michael O'Donnell, a marketing consultant of Cherrywood Lawn, Clondalkin, Dublin.

Mr O'Tuathail, who appeared with John Smith and solicitor Cormac O Ceallaigh, said the undertakings would continue until 2 February when the linked defamation and injunctive proceedings would be heard.

Judge Jacqueline Linnane today addressed all of the parties in the Circuit Civil Court, which is now handling the case.

He told them the clock had already started ticking on a mounting legal bill both on High Court and Circuit Court costs.

"I would have thought that a prudent manner of dealing with this would be for people to be reasonable and sit down and talk about it," she said.

"Don't be surprised if there is a massive legal bill at the end of the day if notice is not taken of what this court is saying."

She said the costs bill had started "tick, tick ticking" and warned all of the parties to hear her words.

"Be reasonable and try to reach a solution here to save some money. You can reach an accommodation that is acceptable to each side," she said.

Barrister Frank Beatty, counsel for Ms Collins and Mr O'Donnell, had told a pre-Christmas sitting of the High Court that Ms Collins had been intimidated by the two former church members as she handed out anti-drugs leaflets outside the Church of Scientology premises in Middle Abbey Street, Dublin.

He said Ms Collins and Mr O'Donnell were scared and frightened "and they should be".  

Mr O'Tuathail told the court his client denied doing anything wrong. 

The two cases have been adjourned for hearing until 2 February.