Irish woman and green card holder Cliona Ward, who spent almost three weeks in an ICE detention center after returning from a trip to Ireland, has shared a statement of gratitude following her release on May 7.

Cliona, who has been a green card holder for more than 30 years and has a valid card until 2033, was stopped by US Customs and Border Protection (CBP) at San Francisco International Airport (SFO) on March 19.

She was returning to California from Ireland, where she had accompanied her step-mother to visit her father, who is battling dementia and is at the end of his life.

She was eventually released from an ICE detention center in Washington following a court appearance on May 7.

The case gained huge media attention both in Ireland and in the US. Cliona's sister, Orla Holladay, launched a GoFundMe to raise awareness as well as the cost of Cliona's legal fees. To date, the page has raised nearly $50K.

In her first comments since her release, Cliona thanked her family and the public for their support.

"My warrior sister, defender of justice!!!! Could this be a calling for you? You dive in deep and figure out what to do next...I cannot thank you enough for what you did for me, and now continue to fight for justice served.

"Everyone should have the opportunity to prove their innocence. If proven guilty, at least they had the opportunity to be heard. I must secure my status before diving deep, so thank you for being my voice for them. I love you so much, my Warrior, my defender, my sister, my anam cara. There is truly no one in the world like you, and I am truly blessed!"

Cliona's sister, Orla, told NBC Bay Area that Cliona had been detained because of her prior criminal record, which stretches from 2003 to 2008.

Orla separately told Newsweek that Cliona's prior criminal record includes six cases - two felonies for possession of drugs in December 2007 and January 2008, and four misdemeanors.

The convictions, however, had been expunged at the state level.

Orla told Newsweek that Cliona, who had struggled with addiction, has now been sober for more than 20 years.

After being held by customs for three days at SFO, Cliona was released so she could obtain documentation to prove her records had been expunged in California. 

After getting the documentation, Cliona returned to SFO Customs for an 'administrative hearing' on April 21 - however, the Irish woman was again detained by customs and told she would have to argue her case in front of an immigration judge.

Cliona was then sent to an ICE detention facility, the Northwest Detention Center in Tacoma, Washington.

Cliona's attorney, Erin Hall, told RTÉ's Prime Time that an application was made in California on Friday for the original convictions to be formally vacated in a manner that would be recognized at a federal level.

A California judge agreed to the application, which allowed Hall to subsequently file a motion to terminate the immigration proceedings.

Orla, who is now looking after Cliona since her release, has previously said her sister is suffering from PTSD and is taking time to heal both physically and emotionally.