The father-in-law of Shaker Aamer has told ITV News that his daughter is "delighted" that the former Guantanamo detainee is back home on British soil.
Saeed Siddique said his daughter was "of course delighted" and "cheerful" at the release of her husband after almost 14 years imprisonment.
Siddique, who said he had not yet seen Shaker, also confirmed that his son-in-law had spoken to his children on the phone but had not been able to see them.
Shaker Aamer could be set to bring legal proceedings against the British Government "over its alleged complicity in his mistreatment", according to reports.
A source claimed "proceedings were initiated some years ago" on Shaker's behalf that "will now, undoubtedly, be progressed."
The father-of-four was the last British resident held at Guantanamo Bay up until his release this week after serving 14 years in the military prison.
Shaker Aamer is "suffering from post-traumatic stress disorder", one of his lawyers has confirmed.
Speaking on the former Guantanamo Bay prisoner's first full day of freedom back in Britain, lawyer Ramzi Kassem said his client was suffering from "physical and psychological" conditions following his release.
Kassem told BBC Radio 4's Today programme: "He suffers from a number of conditions both physical and psychological, including post-traumatic stress disorder on the severer end of the PTSD spectrum."
Aamer is currently undergoing medical tests ahead of being reunited with his children.
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ITV New at Ten presenter Tom Bradby reports.
An Imam and family friend has said that Shaker Aamer's family is "really excited" about being reunited with him and that they have "years of catching up to do".
Sheikh Sulaiman Ghani, Imam of Tooting Islamic Centre, said he remembers Shaker as a man with a "smiling face" and said he was always cheerful.
Sulaiman Ghani has not seen Shaker Aamer in more than 15 years.
Shaker Aamer has landed back in the UK after being released from Guantanamo Bay.
The 46-year-old had spent 14 years in the military prison but was never tried for any offence.
ITV News' Rohit Kachroo reports on Shaker Aamer's release.
The father-in-law of Shaker Aamer has told ITV News that the former Guantanamo detainee is feeling his release is "unbelievable".
Saeed Siddique said that Shaker Aamer is very happy at being returned to the UK and will join the rest of his family in the next few days.
He added that his daughter is "delighted" at being able to be reunited with Shaker soon.
Shaker Aamer has paid tribute to his supporters on his return to the UK.
Mr Aamer, who was the last British detainee at Guantanamo Bay, said: "Without their devotion to justice I would not be here in Britain now".
He thanked Allah, his wife, family and children, and his lawyers, as well as everyone else who supported him and campaigned for his release.
I feel obliged to every individual who fought for justice not just for me but to bring an end to Guantanamo.
Without knowing of their fight I might have given up more than once; I am overwhelmed by what people have done by their actions, their thoughts and their prayers and without their devotion to justice I would not be here in Britain now.
The reality may be that we cannot establish peace but we can establish justice. If there is anything that will bring this world to peace it is to remove injustice.
Former Guantanamo Bay detainee Moazzam Begg says he is overjoyed at Shaker Aamer's release.
Mr Begg said that Shaker Aamer would have to 'relearn' to be a free man after being detained for so long and not having seen his family in many years.