Engineers may have had evidence as early as January of a small gas leak that threatens to delay the next space shuttle flight, the shuttle launch director said Tuesday.

Bob Sieck said that before Christmas last year a pressure check was made on the oxidizer tank in an engine compartment, and a second reading was taken about two weeks later."There was a pressure drop of about 16 pounds per square inch between the two readings," said Sieck in an interview. "We are reviewing all procedures and documentation and equipment associated with that event."