Andy Samuels was engulfed in flames on Monday night when a patio heater caught fire on the balcony of Liam's penthouse flat in East London, prompting the One Direction star to rush to his aid.
"We are so grateful to Liam because he saved his life," said Andy's stepfather, Matthew Baker, to the Mirror. "The lantern just exploded as Andy was lighting it and took the full force of the flames. Liam helped him by beating out the flames and dousing him with water. He acted quickly and swiftly."
"What happened was absolutely awful," added Matthew. "My son is very poorly. I've spoken to Liam on the phone and he told me exactly what happened. He is very shocked himself. It's bad enough but it could have been a lot worse."
Andy's girlfriend Daisie Smith took to Twitter to thank all those who have sent their support in the days following the accident.
"Thank you so much for all of your lovely messages and prayers," said Daisie. "On behalf of Andy's family and I, we'd like you to know he is in a stable condition."
The incident left Andy, who grew up with Liam in Wolverhampton, with 20% burns to his hands and face while two other guests also suffered superficial burns to their hands.
The fire at Liam's £2million flat in Canary Wharf reportedly destroyed 80% of the balcony and it took 35 firefighters to tackle the blaze.