A mother and her son, who was adopted shortly after his birth 57 years ago, have begun a legal action against a Catholic adoption agency and the State, alleging he was illegally adopted.

Tressa Donnelly Reeves, who is 79, and her son André Donnelly, who was given the name Patrick Farrell by his adoptive parents, also claim she was fobbed off and deceived for many years about his identity and location.

They also claim the defendants failed to provide them with information about each other that they were entitled to.

Her son suffered serious physical abuse at the hands of the man he knew as his father, the High Court heard.

Ms Donnelly Reeves, who lived in Surrey in England with her staunchly Catholic parents, was about to turn 21, when she became pregnant.

Arrangements were made for her to travel to Ireland and she ended up in a house in Clontarf in Dublin through the St Patrick's Guild Adoption Society, which was run by the Sisters of Charity.

Her son was born at a clinic in Clontarf on 13 March 1961.

The court was told that she was told not to touch the baby as it was intended to put him up for adoption and it would be "bad for the child".

She baptised him herself that night, and gave him the name André, hoping that such an unusual name would make him easier to trace.

The following day the baby was removed from her and just over a week later she was brought to a house in the city centre where she signed various forms purportedly consenting to an adoption.

She was put on a flight back to England later that same day.

Senior Counsel Éanna Mulloy said the documents were "legal nullities" and had none of the safeguards required. Details about Ms Donnelly's address and age were fudged.

The court heard that Tressa Donnelly Reeves married and had other children but began looking for her son from the mid 1970s onwards and made visits to Ireland seeking information.

The nuns at St Patrick's Guild told her there was no record of the boy's birth and she must be mistaken about what had happened.

She was also told he may have been taken to the US.

She eventually received a letter telling her that the child had been placed with an Irish couple - James and Maeve Farrell from Carlow - who had "taken him as their own" and "no formal adoption order had been made".

A birth certificate registering his name as Patrick Farrell with an incorrect date of birth had been issued, the court heard.

It was also told that for year after year, Ms Donnelly was fobbed off in a variety of ways because St Patrick's Guild had given a "power of veto" to the adoptive parents.

Mr Mulloy said she was told she was not entitled to information on the basis of a right to privacy that the Farrells were claiming.

He said the pretence that this adoption was some kind of legal transaction was wholly devoid of any legal substance and Ms Donnelly's son, and another child, had been taken by wrongful means.

Mr Mulloy said the defendants procrastinated and prolonged the "agony" of the separation of Ms Donnelly Reeves and her child.

There was obfuscation, "smooth fibbing" and brushing off taking place.

It was January 2013 before Ms Donnelly Reeves and her son were reunited in a meeting the court was told she had craved for years.

She, her son and her three surviving daughters have been together on and off since then, the court heard.

Mr Mulloy said Mr Donnelly, or Mr Farrell as he is also known, had had a hellish existence growing up.

His adoptive father was extraordinarily given to violence on both his wife and his son.

André or Paddy had been hit with implements and on one occasion when he lost a handball match, the man he knew as his father had broken his right hand. On another occasion he knocked out his front teeth.

Although he had been quite good in school, he was taken out of school after the Intermediate Certificate.

The court heard he went on to get a good job working on the Luas construction works.

But the news of his real background, had sent him into turmoil as he contemplated what he had missed out on.

André or Paddy told the court that finding out he had been adopted after more than 50 years was a bombshell.

He said it did not sink in for quite a while afterwards. He said "you couldn't write it", at his age, being Paddy Farrell and then next minute being told he was André Donnelly.

He said he met his birth mother in January 2013 in the offices of the Adoption Authority.

The meeting inside was "very sterile," he said. But outside they went for a coffee and he had "a good old natter" with his mother and his aunt.

Since then he has been in regular contact with them and his three sisters.

He said the registrar general in charge of registering births had offered to assist him if he wanted to change his identity to André Donnelly but he said he did not know what to do.

It was not a simple matter of "swapping over," he said, and everyone in his family would be affected.

He said it had been tough at home for the past years. He had been preoccupied with all this and could not concentrate on his family. He had to leave his job and take a "savage" pay cut.

Mr Farrell told the court about a number of incidents in his childhood where his adoptive father had beat him or his adoptive mother. He said his mother doted on him but his father was extremely violent.

He described seeing his father kneeling on his mother's chest and punching her.

He said he had been beaten on his leg with a broken plough point for wearing his good clothes outside and his father had broken his two front teeth and had broken two knuckles on his hand after he lost a handball match.

He said he and his adoptive mother did not resist him and had been conditioned not to resist him.

He said one regret he had was that he had never got to meet one of his birth mother's daughters, his sister, who died a number of years ago. But he had built a monument to her in his garden and got great peace from it.

He said he was trying to make up for the last 50 years of not meeting his sisters and did not know how to do it. They had all done very well in life, he said, and he would have loved to have done the Leaving Certificate but his father took him out of school.

He said there was no comparison between the life they had with his mother and her husband and the life he had in Ireland.

He said he felt very angry towards the institutions responsible for running his mother around the country for years and years as she tried to find him.

Ms Donnelly and her son claim they were duped and cheated through and through.

She claims she was induced to sign a false consent form, her baby was removed from her proper custody, he was wrongfully placed with a couple, without any scrutiny and she was given false information about his whereabouts.

She wants acknowledgement and compensatory damages from the State for the fudge that lasted so long, the court heard.

Her son alleges conspiracy, deceit and infringement of his constitutional rights.

They are seeking compensatory damages against the State for breaches of their rights under the Constitution and the European Convention on Human Rights.

In its defence, St Patrick's Guild alleges that the proceedings have been taken too late.

It also claims that, because the case arises from events in 1961, it would be prejudicial, unfair and contrary to natural justice to allow the proceedings to continue because the ability of St Patrick's Guild to defend the case and have a fair trial has been significantly undermined.

The guild denies all the claims made by Ms Donnelly and her son. The State defendants also deny the claims.