Vanessa Hudgens under investigation for allegedly defacing Sedona Red Rock

Vanessa Hudgens is between a rock and a hard place after an alleged act of love has brought her under fire.

The 27-year-old actress and her 24-year-old boyfriend, Austin Butler, allegedly carved their names in a heart into a rock formation in Sedona, Arizona over Valentine's Day weekend, but the gesture might have broken a federal law.

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A public affairs officer for Coconino National Forest tells ET the incident involving Hudgens and Butler "is under investigation."

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"Officials at the Coconino National Forest became aware of the incident [Monday] when the media alerted them of the situation," the officer tells ET. "There is no deadline for this investigation -- it takes as long as it takes. The maximum punishment for this is $5k and/or 6 months behind bars."

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ET has reached out to Hudgens' rep for comment.

Eyebrows were raised after Hudgens posted a picture of the carving on Instagram, but the post has since been deleted.

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