HomerJ,
Sometimes it may be possible to recover them if the automated cleanup routine hasn't been run on the backside already. If it has been over 24 hours since then you can pretty much guarantee that it probably has run as it is supposed to be run at least every 24 hours by the system automatically.

In this case then you'd need to gather your previous backups and get the information from there. If the backups are scheduled and performed routinely then you should have access to the information easily and to a recent backup. The things to be aware of is that if you restore from the backup then you will lose any data that has been changed or added since the time of said back up.

You then have the option to restore the project backups into a different domain or project to not affect the current project and then copy the information over to the current project. You need to then be aware of the fact that all coverages and linkages are maintained on the back end and they will be lost when copying across as there is no way to maintain them.

When you copy an entity from one project to another since the entity did not originate within the project it is created new during the copy process. What happens is that the entity gets a new ID and is added to the new projects repository during the copy. However since it is a new entity, any back end linkages that were instituted in the prior project no longer exist (this includes requirement, test lab, test run, and defect coverages and linkages that were in tact in the prior project). I mention this as a reason to restore the older project and use it as a starting point as by restoring the prior project the linkages would remain in tact (therefor the run coverage would be maintained), and that by copying to the new project all the older information would be broken for linkage. This also applies to moving the new information from the original project (that created since the old project had last been backed up) to the new project as the same linkages would be broken during the copy and the linkages would need to be reestablished and that the run data since the last would also be lost as it is linked on the backside. By maintaining a back up of the project with the new data in it, you still have proof but only in archive form and not within the test lab itself.

How you wish to proceed would be an operational choice, but these are the only methods available to you. I hope this helps with your issue.

Dan