The 33-year-old man complained of itching all over his body as he tried to sleep at night, and later died of heat attack.
Bailey woke in the morning, and discovered him dead in bed beside her.
The mum of four called paramedics, but they could not revive him.
"He was a strapping lad," British tabloid The Sun quoted Andrew's mother Pamela as saying.
"We can only put it down to the sauce.
"After making it, he stuck his finger in to test it, and went to wash it, saying, 'Wow, that's hot'," she added.
Andrew's sister Claire revealed that the contest was planned and her father John had especially grown chillis for the contest.
"The contest was planned. Dad grew the chillis especially. Andrew ate them with a plate of Dolmio," said Claire.
"It wasn't a proper meal because he'd already eaten lamb chops and potato mash after work.
"He got into bed at 2.30am and started scratching all over. His girlfriend scratched his back until he fell asleep. When she woke up he'd gone."
"It's incredible. Who'd have thought he could die from eating chilli sauce? He loved cooking and wanted to be a chef.
"He used chillis to make Thai dishes but never anything this hot.
"We don't know of anything else that could have caused his death. He was perfectly healthy and the post mortem showed no heart problems," she added.