The launch of the Passport Service (UKPS) biometrics trial was delayed by more than two months because of technical glitches.

The pilot was originally scheduled to start in early February but did not go live until late April.

The system, developed by supplier Atos Origin, was fully tested before delivery but suffered from a series of hardware, software and usability problems, which led to "inconsistent enrolment", according to the submission from the UKPS to the Home Affairs Select Committee last week.

"Remedial actions to cure these problems on-site continued for several weeks when, after further tests, the system was withdrawn and given back to Atos Origin for further development and reconfiguration," said the submission.

There were major changes to the iris, facial recognition and fingerprint elements of the scheme.

"This is an untried use of three biometrics working in one application so it is absolutely essential we get the first instalment right before we rolled out the trial," said a spokesman for the Home Office.

"We went through a thorough testing process with the equipment in order to make sure it was bedded in properly, which was the most appropriate professional approach to ensure any trial was properly configured before we took it into the live situation."

The pilot, which is due to run until September, aims to take biometrics from 10,000 members of the public to test both the technology and the enrolment procedure.

The trial's results will affect both the release of biometric passports from 2005 and ID cards from 2007-8.