O&O DiskImage currently requires the Bitlocker recovery key in order to access the drives.
Restore
If the entire hard drive is encrypted (and backed up), recovery can also be done without first entering the Bitlocker recovery key. If only a single drive is to be restored from the backup, access must be gained by entering the Bitlocker recovery key.
Use the command line (“cmd”) for this:
manage-bde -unlock x: -RecoveryPassword
Where x represents the drive and the recovery key must be entered after RecoveryPassword.
Even if it says "Recovery Key", it just does "unlock".
It should be noted that the status of the encryption depends on the selected backup method
With the default setting "Used Sectors", the encryption information is not backed up. If restored, Bitlocker would not be active. To create the backup including the encryption information, select the "Direct forensic" method in the backup options for the drive backup. This backs up all sectors of the hard drive, including empty sectors. This means that the backup is larger, but the hard disk remains encrypted during the restore.