Spoiler alert! The director and star of Irish drama Amber which ended last night with an audience of 779,000 have defended the open-ended conclusion of the hit series.

The four-part drama about missing Dublin teenager Amber Bailey was screened over four consecutive nights on RTÉ One and attracted audiences of over 700,000.

The stars of the show have defended last night's ending as "controversial but real to life".

Tweeting from their @AmberDrama account, RTÉ said: "So Amber was never found. This is the reality for many families. Sometimes there are no simple answers."

Amber director Thaddeus O'Sullivan says that it is very clear what happens to the missing teen at the end of the show.

Speaking to the Herald he said "I think people get a very strong and clear ending to the series. Although yes, it is ambiguous in story form, I think it is very clear on where we stand on it and what happened to her."

Some disappointed viewers took to Twitter last night to voice strong opinions at the conclusion of the show, with one disgruntled viewer tweeting, "RTE just stole four hours of my life." while another said: "If that is seriously the ending I am suing RTE."

15-year-old actress Lauryn Canny who played Amber also defended the controversial ending, describing it as "very brave".

"I personally loved the ending and thought it was very realistic because a lot of missing person cases don't get closure." she has said.

Episode one of the series attracted 656,000 viewers with 676,000 for episode two, 732,000 for part three, and 779,000 watching last night's concluding episode.

Amber will be shown on BBC later this year. All four episodes of are available to view on the RTÉ Player.