Mystery surrounds the disappearance of Nancy Guthrie, the mother of US TV host Savannah Guthrie.
The 84-year-old went missing from her home in Arizona under suspicious circumstances nearly two weeks ago.
She was last seen at her home near Tucson on the evening of 31 January and was reported missing the following morning.
Investigators said they had found signs of forced entry and believe she was taken against her will.
Now the FBI has released CCTV footage showing an "armed individual" at her front door, and a man has been detained and released.
Here's everything we know so far.
What do we know about the disappearance?
The NBC News anchor's mother was last seen on the evening of Saturday 31 January, when she was dropped off at home by family after having dinner with them, the sheriff's department said.
Ms Guthrie, who lives alone, was then reported missing by her family the next day, after she did not attend church.
Police have said Ms Guthrie has difficulty walking, a pacemaker, and requires daily medication for a heart condition.
Her family and authorities have said they are concerned her health could be deteriorating by the day.
Footage recovered from Guthrie's doorbell camera
Police have said there were signs of forced entry at the property, and DNA tests showed blood found on Ms Guthrie's front porch matched hers.
Investigators also found her doorbell camera was disconnected early on 1 December, with software data recording movements at the home minutes later.
Investigators said they were unable to recover the footage because Ms Guthrie did not have an active subscription to the service.
Then on 10 February, FBI director Kash Patel said footage had been recovered "from residual data located in backend systems".
Mr Patel did not say how the FBI was able to collect the video, or why it took so long to retrieve.
The footage showed an "armed individual" in a mask standing outside of Ms Guthrie's home. At one point, they appear to try and cover the camera up.
Driver detained
A man was detained during a traffic stop and questioned by authorities in relation to the case on 10 February, according to the local sheriff's office.
Speaking to reporters outside his house, the site of a police search that night, Carlos Palazuelos, who has since been released, said he didn't know who Savannah Guthrie was.
The authorities said on 11 February that the search at the man's property was over and that the investigation was ongoing.
Ransom notes
At least three media organisations reported receiving apparent ransom notes during the week after Ms Guthrie's disappearance, which they handed over to the police.
One man was arrested in Los Angeles accused of sending texts to Ms Guthrie's family asking about Bitcoin demanded in a reported ransom letter, NBC News reported.
The messages were not linked to the other reported ransom demands.
Read more:
Why Nancy Guthrie's doorbell footage has led to privacy concerns
Heith Janke, the FBI chief in Phoenix, said details in the messages to news organisations included a demand for money.
At least one note mentioned a floodlight at Ms Guthrie's home and an Apple watch, he added.
KOLD-TV in Tucson later said it received a new message, via email, linked to Ms Guthrie's case. The station said it could not disclose its contents and the FBI said it was reviewing the message's authenticity.
The Guthrie family previously said they were willing to pay for their mother's return after an apparent ransom note asked for $6m (£4.4m).
The FBI said it was not aware of ongoing communication between Nancy Guthrie's family and the suspected kidnappers.
FBI releases more details and doubles reward
The FBI released new information about the suspect on 12 February, describing the person as "male, approximately 5ft 9in-5ft 10in tall, with an average build".
They also said he was seen wearing "a black, 25-liter 'Ozark Trail Hiker Pack' backpack" in the footage shared by law enforcement.
The FBI also said it is increasing its reward up to $100,000 (£73,400) for information leading to the location of Ms Guthrie.
The reward, which was previously up to $50,000 (£36,700), also applies to information that leads to the arrest and conviction of anyone involved in her disappearance.
What has Savannah Guthrie said?
Savannah Guthrie shared a video on social media in which she addressed her mother's captor alongside her sister Annie and brother Cameron.
"We are ready to talk," the anchor said. "However, we live in a world where voices and images are easily manipulated.
"We need to know without a doubt that she is alive and that you have her. We want to hear from you, and we are ready to listen. Please reach out to us."
She added: "Our mum is our heart and our home. She is 84 years old. Her health, her heart, is fragile. She lives in constant pain. She is without any medicine. She needs it to survive, she needs it not to suffer.
"Mummy, if you are hearing this, you are a strong woman. You are God's precious daughter."
The TV host told the potential kidnappers her family "will pay" for her safe return.
"We received your message and we understand," she said, speaking alongside her siblings Cameron and Annie in an Instagram video. "We beg you now to return our mother to us, so that we can celebrate with her."
"This is the only way we will have peace," she added. "This is very valuable to us, and we will pay."
Savannah Guthrie co-hosts Today, the morning show on NBC News, the US sister network of Sky News.
She often brought her mother on as a guest. Speaking on the show in 2022 on Nancy Guthrie's 80th birthday, she said: "She has met unthinkable challenges in her life with grit, without self-pity, with determination and always, always with unshakeable faith.
"She loves us, her family, fiercely, and her selflessness and sacrifice for us, her steadfastness and her unmovable confidence is the reason any of us grew up to do anything."
(c) Sky News 2026: Nancy Guthrie: What we know about mysterious disappearance of TV host's mother

'Britain's loneliest sheep', Fiona, gives birth for first time
'Tipping point' reached in creation of brain chips to help 'unlock' minds of people with paralysis
Mandelson would have had 'thorough' vetting process before US ambassador role, says ex-MI6 boss
Extremists jailed for plotting 'deadliest' terror attack on UK Jewish community
How Trump's White House is helping Big Tech fight back against child safety campaigners
Tackling misogyny should be sixth mission of Sir Keir Starmer's government, Harriet Harman says





