Some readers who bought autographed editions of Liza Minnelli’s memoir are questioning whether the legendary singer and actor actually signed the books herself, the Guardian reports.

Minnelli’s memoir, Kids, Wait Till You Hear This!, co-written with Michael Feinstein, Josh Getlin, and Heidi Evans, was published in March by Grand Central. In a starred review, a critic for Kirkus called the book “an old-school Hollywood tell-all with all the trimmings, traumas, and boldface names.”

Purchasers speculated that the books might have been signed with an autopen, a device that replicates signatures.

One collector, Gareth Brown, who bought a signed book at a store in Kent, England, told The Guardian, “When you see footage of Liza today in her own documentary, she is far too frail to have signed a handful of books this accurately, let alone hundreds. I started wondering how many books she must have signed for one to end up in an independent bookshop at an English seaside. I found there was much online discussion about this and many photographs of the signature, all of which look the same.”

In a Reddit thread from March, users of the website also expressed doubt about the signatures, but there was no consensus on the issue.

While Minnelli’s agent and publishers did not comment to the Guardian on the authenticity of the signatures, her publicist, Victoria Varela, responded when asked by the Daily Beast if Minnelli used an autopen, “Absolutely not.”

Michael Schaub is a contributing writer.