Ulamila Cakau, the wife of the head pastor at Sabeto Assemblies of God in Nadi, told the newspaper that Mr Groom had grown up in difficult circumstances in Fiji.
"He had been living on and off the streets for several years when he came across one of our church members [in 2000]," she said.
"He had lost his father and he was devastated by the loss but he also did not want to live with relatives so he adopted a life on the streets."
Mr Groom moved into the Dream Centre in Sabeto, which eventually paid for him to fly to Britain to pursue his dream to be in the British Army.
He joined in 2007 and was deployed to Afghanistan for his second tour of duty in April this year.
Britain's Ministry of Defence said Lance Corporal Groom was protecting his Afghan and British colleagues as they extracted themselves from a successful operation when he was killed by a roadside bomb.
His commanding officer, Lieutenant Colonel James Bowder, said: "Lance Corporal Groom was an outstanding soldier in every respect.
"Tough, keen, and unflappable, he was utterly committed to his fellows and the cause.
"We are all tremendously proud of what he achieved during his time in the regiment, and particularly out here in Afghanistan, where he contributed so much."
A Fijian colleague who also served with British forces, Corporal Joe Roligadra, told London's Daily Telegraph: "I have known Duane since I was 14 and he was always like a big brother to me.
"He was the sort of person who always had your back covered in good times and in bad times."
