Ms Doyle’s husband Rob said she was taken to hospital after he found her “unresponsive”.
It comes after an inquiry into allegations of bullying at the channel.
The probe, conducted by law firm Capital Law, published its report on Wednesday.
It found Ms Doyle’s leadership style to be “dictatorial” and “creating a culture of fear”.
Ms Doyle has previously claimed she suffered “a sustained pattern of retaliation, unfair treatment, and wider bullying” at the hands of S4C’s chairman.
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In a statement issued on Wednesday, members of the S4C Authority – the body which oversees the management of the broadcaster – said they “would like to say sorry to those who have had to tolerate unacceptable behaviours in the workplace and for the upset that this has caused”.
S4C said the chairman had nothing further to add to Wednesday’s statement.
Mr Doyle said the report was “heavily biased” and that its framing was “cruel”.
He added the last 24 hours had seen his wife “torn apart in the media after an exceptional 30-year career because of a one-sided report”.
Mr Doyle claimed the report was “designed to be an assassination of her character”.
A DCMS spokesperson said: “Our thoughts and prayers are with Ms Doyle and her family at this incredibly difficult time, and we wish her a speedy return to health.
“We expect the board of S4C to address the issues identified in the independent investigation by Capital Law as a matter of urgency. We have been in regular contact with S4C throughout this investigation and will remain so.
“Public service broadcasters, like every organisation, have a responsibility to uphold a duty of care to all employees.”
S4C was launched in 1982 after a campaign to establish a Welsh-language channel.
“Sian was so proud to have been asked to come out of retirement to lead an organisation that, as a young girl, she campaigned to set up,” Mr Doyle said.
“But that pride turned into frustration, and then to disappointment, fear, and finally despair.”
He said he had “watched in horror and disbelief” as his wife had been “hunted over the last seven months”.
“The person represented in yesterday’s supposedly ‘independent’ report was unrecognisable from the woman I’ve loved for the past 37 years, or the woman her friends and former colleagues know,” he added.
A spokesperson for S4C said the news about Ms Doyle was “very worrying”.
“We are thinking about her and the family,” they said in a statement. “We have offered our support to the family during this difficult time.
“Our hope is that she will recover quickly, and we wish her all the best for the future.”
Angelina Jolie says although she appreciates being an artist, she would prefer for her legacy to be “a good mother” and to be known for her “belief in equality and human rights”.
The Oscar-winning actress stars as Maria Callas in the new Pablo Larrain film about the opera singer’s life.
She has called Maria “the hardest” and “most challenging” role she has had in her career and put months of preparation into immersing herself into the world of opera.
Jolie, who recently reached a divorce settlement with actor Brad Pitt, told Sky News: “To be very candid, it was the therapy I didn’t realise I needed. I had no idea how much I was holding in and not letting out.
“So, the challenge wasn’t the technical [side of opera], it was an emotional experience to find my voice, to be in my body, to express. You have to give every single part of yourself.”
The biopic combines the voice of the Maleficent actress with recordings of Maria Callas.
Jolie believes it “would be a crime to not have [Callas’] voice through this because, in many ways, she is very present in this film”.
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Who was Maria Callas?
Born in New York in 1923, Maria Callas was the daughter of Greek immigrants who moved back to Athens at the age of 13 with her mother and sister.
After enrolling at the Athens Conservatory, she made her professional debut at 17 and went on to become one of the most famous faces of opera, travelling around the world and performing at Covent Garden in London, The Met in New York and La Scala in Milan.
Callas’s final operatic performance took place at Covent Garden in 1965 when she was 41 but she continued to work conducting master classes at Juilliard School, doing concert tours and starring in the 1969 film Medea.
Written by Peaky Blinders creator Steven Knight, Maria focuses on the artist’s final years in the 1970s when she moved to Paris and disappeared from public view.
She died on 16 September 1977 at the age of 53.
Jolie on changing motivations as an actor
Maria follows the life of an artist fully consumed by the art she creates and even remarks that “happiness never developed a beautiful melody”.
Reflecting on her own life in the spotlight, Jolie said she noticed her own career motivations change over the years.
“There’s this kind of study of being human that we do when we create, and we communicate with an audience because our work is not in isolation – it’s a connection.
“I think when I was younger, I had different questions about being human and different feelings and now as I’ve gotten older, I understand some things and now I have different questions.
“It’s a matter of life, right? And so maybe that’s interesting that this now is a character really contemplating death and really contemplating the toll of certain things in life that I, of course, couldn’t have understood in my 20s”.
A family affair
Two of Jolie’s children, Maddox and Pax, took on production assistant roles during the filming of Maria and witnessed their mother perform opera for the first time in public.
She says the film allowed them to create new experiences together and for her children to see her approach to playing a difficult role.
“Everyone in my home, we all give each other space to be who we are and we’re all different.
“I’m the mom, but I’m also an artist and a person and so my family has been very kind and gives me their understanding. They make fun of me, and they support me and just as you’d hope it would be.”
She adds: “When you play somebody who is dealing with so much pain, it’s very important to come home to some kindness.”
Sam Moore, who sang Soul Man and other 1960s hits in the legendary Sam & Dave duo, has died aged 89.
Moore, who influenced musicians including Michael Jackson, Al Green and Bruce Springsteen, died on Friday in Coral Gables, Florida, due to complications while recovering from surgery, his publicist Jeremy Westby said.
No additional details were immediately available.
Moore was inducted with Dave Prater into the Rock and Roll Hall of Fame in 1992.
This breaking news story is being updated and more details will be published shortly.
Neither star has publicly addressed the rumours but Tom’s comedian father, Dominic Holland, has now confirmed the pair are set to wed.
He wrote in a post on his Patreon account: “Tom, as you know by now was very incredibly well prepared. He had purchased a ring.
“He had spoken with her father and gained permission to propose to his daughter.”
“Tom had everything planned out… When, where, how, what to say, what to wear,” he added.
Dominic also noted that while most men worry about being able to afford an engagement ring, he suspects his actor son was “more concerned with the stone, its size and clarity, its housing, which jeweller”.
Tom and Zendaya met on the set of Spider-Man: Homecoming in 2016, when they played the titular hero and his love interest MJ, respectively. Their romance was confirmed in 2021.
In his post, Tom’s father admitted fears over whether being in the spotlight could put a strain on the couple’s relationship.
He wrote: “I do fret that their combined stardom will amplify their spotlight and the commensurate demands on them and yet they continually confound me by handling everything with aplomb.”
“And even though show business is a messy place for relationships and particularly so for famous couples as they crash and burn in public and are too numerous to mention […] yet somehow right at the same time, I am completely confident they will make a successful union.”