Whanganui woman Gail Pointon has been keeping chickens for about 20 years but she has never seen an egg like the one she collected recently.
"I contacted the paper back in 2009 when one of the chooks laid a 7.5cm egg but this one measures 9.5cm."
Mrs Pointon said she is not sure which one of her three Red Shaver chickens produced the egg.
"Whichever one it was, I don't expect her to lay for while after that effort."
The home educator said she has not been feeding her chickens anything out of the ordinary so she does not know why one of them produced such an extraordinary egg.