The West Australian couple at the centre of the baby Gammy controversy says his Thai surrogate mother has misled the world over the situation, and they were told when he was born that the boy had only a day to live.

The Bunbury couple - David and Wendy Farnell - say they have been traumatised by a messy legal battle and heavy media attention which has portrayed them as heartless.

Gammy's biological parents allege surrogate mother Pattaramon Chanbua has been telling lies. Credit:AP

In a statement to the Bunbury Mail issued through a family friend, the couple said allegations that they abandoned baby Gammy were lies.

“This has been absolutely devastating for them, they are on the edge,” said the family friend.