A "purification rundown" course operated by the Church of Scientology was neither medically safe nor scientifically verified, the High Court was told yesterday.
Prof Michael Ryan, head of the pharmacology department at UCD, said he could not find any evidence to support the claims in the church's documents about the course.
To suggest it could get rid of radiation and toxic compounds was not supported by scientific facts, he said.
He was giving evidence in the continuing action by Ms Mary Johnston (40), who operates a sports equipment centre at Westwood, Foxrock, Co Dublin, against the church and three members of its Dublin mission for alleged conspiracy, misrepresentation and breach of constitutional rights.
Yesterday the court was told Ms Johnston had experienced a burning sensation as a result of participating in the purification rundown course and had been told this was a clearance of old sunburn.
Prof Ryan said there was no scientific evidence to support that contention.
Mr Michael Cush SC, for Ms Johnston, submitted that the claims made by the church in its documents concerning the purification course were false and the risks involved many and varied.
Prof Ryan said the claims made in the church's documentation were not scientifically verified, and the programme was not medically safe.
In reply to Mr Justice Peart, he said some of the volumes of vitamins involved would be significantly higher than those recommended for normal nutrition. He said this was the case as regards vitamins A and D. The potential risk for higher levels included acute dizziness and headaches, he added.
Mr John Trainor SC, for the defendants, said they would be producing a doctor to give evidence that hundreds of people go through the course without reporting any adverse effects.
He said more than 290,000 people had undergone the course without any problems.
The case continues today.