A former Irish Defence Forces member accused of membership of so-called Islamic State (IS) has won an appeal against a ban on her entering the UK.
Lisa Smith, from County Louth, had been the subject of a Home Office-issued exclusion order since December 2019.
The order was made on the grounds of public security.
The 39-year-old is charged with membership of the IS terror group and funding terrorism. She has denied the charges.
Ms Smith is currently on bail in the Republic of Ireland ahead of a scheduled trial in the country's Special Criminal Court next January.
Her father is originally from Belfast and her case against the Home Office hinged on whether she was entitled to enter the UK as a consequence of that fact.
Both sides in the case before the Special Immigration Appeals Commission (SIAC) accepted that the UK had a legal right to exclude non-British citizens from European Economic Area (EEA) countries, including Ireland.
However, that right does not cover those of dual nationality and Ms Smith's legal team argued she was entitled to the rights of a dual national as a consequence of her father's birthplace.
The case involved argument on the nationality rights conferred under the 1998 Good Friday Agreement and differences in how the law treats married and unmarried parents, given Ms Smith's father was not married to her mother when she was born.
The SIAC allowed Ms Smith's appeal against the exclusion order in a written judgment on Friday.
Entry ban was 'unlawful'
Her solicitor welcomed the decision.
"Today's ruling is hugely significant for the upholding of basic human rights principles, which include the right to be free from discrimination," said Darragh Mackin.
"The decision to exclude our client was discriminatory and contrary to the basic principles underpinning the Good Friday Agreement.
"As an Irish citizen who resides in a border town, it was always asserted that to restrict her from travelling across the border was unlawful and could not be stood over.
Mr Mackin added that the judgement reinstated Ms Smith's basic rights to travel to Northern Ireland at her convenience.