Those affected by the bloody crimes of the Islamic State group have called for justice following the capture of the alleged "Beatles" jihadis.
Whether Alexanda Kotey and El Shafee Elsheikh, from west London, will be brought to trial and where is unclear.
Bethany Haines, daughter of British aid worker David, who was executed in 2014 after being held captive by the notorious terror cell for 18 months, said she wants the pair locked up following their capture near the Syria/Iraq border.
She told ITV's Good Morning Britain: "In my opinion, they shouldn't be breathing but that's not really a realistic kind of expectation. I think that they should be locked up with the key thrown away and never to be released."
She added: "It was always kind of the unanswered question as to where they were and could they do this sort of thing again? And yes, this sort of thing might happen again but the specific people that carried it out before have now all been caught and I think it will bring a lot of closure to all the families."
She said they should be "made an example of" to show "there is zero-tolerance for terrorism and these sort of crimes".
One former hostage has said the pair should be brought before a British court, while the mother of murdered US journalist James Foley said she would like to see them face justice in the United States.
Diane Foley's son appeared in a video released in August 2014 alongside the now-deceased Mohammed Emwazi, known as Jihadi John.
She told BBC Radio 4's Today programme: "I would like them to be brought to trial in the US but as long as they are brought to fair trial and detained and justice is served I would be most grateful."
French journalist Nicolas Henin was held hostage by Islamic State for 10 months and believes "The Beatles" were among his captors.
He told the Today programme: "I would like to see them brought back to Britain, just like I would like to see all other European jihadis brought back to their home countries, to be judged fairly in their home country.
"Because the worst thing we can do with a terrorist is to deprive him from his right because then you make the terrorist a victim."
The New York Times, which broke the news of the capture, reported that Kotey and Elsheikh have had their British citizenship revoked - but this has not been confirmed by authorities in the UK.
The Government has the power to strip an individual of their UK citizenship in some circumstances.
The Home Secretary can deprive someone of their British citizenship if they are satisfied taking the measure is "conducive to the public good", such as in national security cases.
This is an option for dual nationals but removal of citizenship on these grounds is not allowed if the person in question would be left "stateless" - except if they have been naturalised as a British citizen, have acted in a manner that is "seriously prejudicial to the vital interests of the UK" and where there are reasonable grounds for believing they could acquire nationality of another state.
Between 2006 and 2015 there were 81 deprivations of citizenship orders made, including 36 made on the "public good" basis.