The reports indicate the enigmatic musician is being tested to determine the cause of “internal hemorrhaging,” though the band’s American management could only confirm that he’s been sick.

A rep contacted by Pollstar May 10 would not confirm the cancellation of the European dates but that could change.

GNR – in the midst of a comeback year – was to launch the trek June 1 at the Rock Im Park festival in Germany, with subsequent stops in England, Scotland, Spain, Denmark and Sweden, before wrapping up June 28 at the Roskilde Festival near Amsterdam.

Buckethead is instantly recognizable onstage with his trademark KFC chicken-bucket hat and “Phantom of the Opera”-style white mask.

He joined Guns N’ Roses co-founder Axl Rose, Tommy Stinson (ex-Replacements), Brian “Brain” Mantia (Primus), Chris Pittman (Replicants), Paul Tobias (aka Paul Huge) and Robin Finck (Nine Inch Nails) last year to form the latest incarnation of the fractious L.A. rock outfit.

The band is expected to release the long-delayed Chinese Democracy in the near future, though no date has been set.