It has been four years since Azmat Begg has seen his son Moazzam.
Moazzam Begg was held in solitary confinement
And on Tuesday as he watched the plane which brought his son home touch down following his release from Guantanamo Bay, he was clearly emotional.
With tears in his eyes he said it was a "nice thing to watch" and added he was looking forward to seeing his son.
But his three-year nightmare is not yet over. Moazzam, and three other fellow British ex-detainees, were arrested on arrival in the UK.
Mr Begg said he had constantly been concerned about his son's health.
He told BBC News: "He has been a prisoner in solitary confinement for so long, I do not know how he survived .
"I recently learned he was in a cell which was 4ft by 6ft. He was tortured for three years.
"I do not know how badly he was treated or how badly he is.
"He has mentioned he was alright but I think he was not giving me all the information. He has been keeping all the pain and suffering from me. He has been suffering badly.
"I think they should have given him a little more time to gather himself before they take him to the police station and ask him questions."
Mr Begg says he has been told he will be able to see his son for the first time on Wednesday.
He says his son will be excited to be back in the UK.
"He will be looking forward to seeing his family now. I will welcome him back and tell him that I love him."