Human error is being blamed for Valerie Adams and Lucy van Dalen being left off the original start list in their respective competitions.
The New Zealand Olympic Committee's fronted media to explain the gaffe.
They say Athletics Sport Manager Raylene Bates accidentally left the boxes blank when they should have been ticked to confirm the two athletes were competing.
Chef de Mission Dave Currie says he's talked to her at length to find out what happened, she thought she'd ticked them.
He admits Adams and van Dalen, who's running in the 1500m, were let down.
"There was a process that had to be put in place and yes she's been let down, as was the other athlete that was on that form that day."
Dave Currie says Ms Bates is incredibly distraught over the incident.