Technicians sorting through debris from the space shuttle Columbia have found hundreds of worms from a science experiment aboard the shuttle, NASA said Wednesday.

The C. elegans worms were found in the wreckage in Texas several weeks ago, but no one opened the containers until this week.

"To my knowledge, these are the only live experiments that have been located and identified," said Bruce Buckingham, a NASA spokesman at the Kennedy Space Center.

The pencil tip-sized worms and dead moss cells were found in a locker from the mid-deck of the shuttle.

All seven astronauts were killed when the shuttle broke up on Feb. 1. Columbia contained almost 60 scientific experiments.

Buckingham said the worms have a life cycle of between seven and 10 days. The ones found were four or five generations old.

The worms were part of an experiment testing a new synthetic nutrient; the moss was used to study how spaceflight affects cell growth.

Scientists are analysing the samples and don't yet know if they will have any scientific value.