Helen Forde (see earlier posting) says they were lost. Urban myth, though:

http://astrogeology.usgs.gov/Projects/LunarOrbiterDigitization/: web page of the Lunar Orbiter Digitization Project gives sone techie details. “Five Lunar Orbiter missions were launched in 1966 and 1967 to study the Moon. The first three missions were devoted to mapping potential lunar landing sites. The fourth and fifth missions were intended for broader scientific goals. Lunar Orbiter 4 photographed the near-side and 95% of the far-side of the Moon. Lunar Orbiter 5 completed the photography of the far-side and collected medium- and high- resolution imagery of 36 preselected regions… The full LO (Lunar Orbiter) dataset consists of 967 medium resolution (MR) and 983 high resolution (HR) frames. Due to their large size, HR frames have traditionally been divided into three sections (referred to as sub-frames). Prior to being placed onboard the spacecraft, the photographic film was exposed with strip numbers, a nine-level grayscale bar, resolving power chart, and reseau marks. The original photograph was scanned into a series of strips onboard the spacecraft and then transmitted to Earth as analog data. Photographic prints from these film strips were hand mosaicked into sub-frame (for HR data) and full-frame (for MR data) views and widely distributed.”

This suggests that there were no earth-bound digi images at all. The images were sent from the orbiter by radio, where they were printed onto paper and hand-mosaic’ed. Digitisation was then not done until this project started.

http://www.lpi.usra.edu/resources/lunarorbiter/processing/: the Lunar and Planetary Institute, which has published the images on the web at http://www.lpi.usra.edu/resources/lunarorbiter/. Some images don’t survice from (say) LO 2 of 1966, “Between November 18 and 25 it produced 211 photographs during 40 orbits, although some photographs were lost during transmission to Earth,” but this is a radio transmission failure, not a digi preservation one.All the successfully transmitted images still survive today (and are on the website).