There are few cars which have stumped the internet quite like the one-off Mercedes S600 Royale.

Images of the vehicle first emerged late last year on the Facebook page of Galpin Auto Sports but were swiftly taken down. Since being first seen in California, it has been spotted in Monaco and was recently captured up close by YouTuber and automotive photographer effspot.

The 5-minute long clip below gives us our most detailed view of the S600 Royale to date and shows off the impressive craftsmanship which has gone into creating it. Among its most eye-opening design elements are the headlights and taillights from the Mercedes-Benz SLS AMG, side grills similar to the SLR and an overall shape harking back to classic W111 and W112 S-Class models.

Screenshot YouTube/effspot

Despite how impressive the model is, no coachbuilder or designer has come forward to say that they created it. Initially, some speculated that Henrik Fisker penned the S600 Royale but he has since denied such reports. Others say that Mercedes tuner Carlsson created it for a member of the Saudi royal family.

What is known is that it is based around a 2014 Mercedes-Benz S550 as evidenced by its VIN number and the unchanged interior.