Annie McCarrick, the Irish American woman who disappeared in Dublin in 1993, is the focus of the first part of RTÉ's new two-part documentary "Missing: Beyond the Vanishing Triangle."

In the first episode of the new documentary, which aired on Monday, May 8, Annie's mother Nancy McCarrick reveals: “We found out from some of her [Annie's] friends that she had been having quite a bit of difficulty with someone she knew and we were totally unaware of that.

"She hadn’t let us know about it. I guess she thought she could handle it herself and things would be alright."

Annie McCarrick’s aunt, Maureen Covell, also says in the documentary: “I was told something in confidence by Anne that someone that Annie had known had struck her when they were in a drunken state.” 

MISSING: Beyond the Vanishing Triangle

This new two-part true-crime series looks at some of the most notorious cases of women who disappeared within a so- called Vanishing Triangle throughout the 1990s.

Part one starts Monday, 9.35pm | @rteplayer | #RTEMISSING pic.twitter.com/txvv60hjxp

— RTÉ One (@RTEOne) May 4, 2023

Also featured in the documentary is Linda Ringhouse, McCarrick's best friend from Long Island who visited Ireland after McCarrick returned there to settle in January 1993.

“We took off on a two-week vacation and she showed me her Ireland," Ringhouse recalled. "We had a really wonderful time."

During the visit, however, Ringhouse says McCarrick told her about an “uncomfortable situation with a person she knew, that had been going on since she had moved back to Ireland."

“There was someone who was not happy that she had moved back to Ireland," Ringhouse added. "It was kind of a deteriorating situation, and it developed after I left.”

After McCarrick's disappearance, Ringhouse and four other friends wrote statements for the missing woman's parents and relatives who had traveled to Ireland to assist in the search.

“Our concerns were put down quickly and faxed over in those first days of the investigation,” Ringhouse said. However, as the documentary reveals, Gardaí claim to have never received the faxes.

Elsewhere in the documentary, Una Wogan discusses how her late mother believes she saw McCarrick with a man in Poppies Café in Enniskerry, Co Wicklow on the day she disappeared, March 26, 1993.

“My mam never doubted that she saw Annie McCarrick with a man in Enniskerry the day she went missing," The Journal reports Wogan as saying.

"Mammy went forward and spoke to a detective and I’m very curious as to why the guards never followed up, never contacted her to get more details."

In new true crime series, MISSING: Beyond the Vanishing Triangle, fresh evidence is presented revealing that on the day Annie McCarrick disappeared, she was seen with a man in Poppies Café, Enniskerry.

Part One starts Monday 9.35pm | @rteplayer | #rtemissing pic.twitter.com/SsvsISBTtv

— RTÉ One (@RTEOne) May 7, 2023

Separately, the Irish Times separately reported on Monday that claims that McCarrick was seen in Enniskerry on the day she disappeared are no longer being treated as reliable with An Garda Síochána’s investigation into the Irish American's murder now focused on Dublin 4.

The Irish Times added that Gardaí are now treating Sandymount as the last place she was seen alive, however, and it is, now, at the center of their inquiries.

The new RTÉ documentary - which also examines the disappearances of Deirdre Jacob, Jo Jo Dullard, Imelda Keenan, and Phyllis Murphy in Ireland - comes not long after Gardaí upgraded their inquiry into Annie McCarrick to a murder investigation.

"It makes a huge difference to hear that her case has been upgraded to a murder investigation," Nancy McCarrick says in the documentary.

"You never know, it might prompt someone to come forward after all these years.

"As hard as they have worked to investigate it through the years, and as many programs as they've done and newspaper articles, but it evidently requires that upgrade in order for a reinvestigation to take place."

Beginning with the disappearance of Annie McCarrick in 1993, new two part crime series MISSING: Beyond The Vanishing Triangle looks at some of the most notorious cases of women who disappeared throughout the 1990s.

Part one, tonight, 9.35pm | #rtemissing pic.twitter.com/unpArtkimY

— RTÉ One (@RTEOne) May 8, 2023

The first episode of "Missing: Beyond the Vanishing Triangle" is now available on the RTÉ Player, while the second episode will air on Monday, May 15.