Vanessa Hudgens under investigation for allegedly defacing Arizona's red rock

Vanessa Hudgens and her boyfriend Austin Butler are facing a hefty fine amid allegations they broke the law by reportedly defacing a rock face in Arizona.

The Spring Breakers star spent Valentine's Day weekend (13-14Feb16) with her beau in Sedona, and during the trip, she showed off a photo on social media of a red rock, in which the lovebirds had carved a heart featuring their names.

"Happy Valentine's Day boo boo bears," Vanessa captioned the shot.

However, the post appears to have landed her in trouble with Red Rock Ranger District officials, as they believe the defaced stone was located in the Coconino National Forest, reports TMZ.com.

Under federal law, people are prohibited from "damaging natural surfaces or property of the United States", with punishments including six months behind bars and/or a $5,000 fine.

Vanessa and Austin have yet to respond to the controversy, but the image, which had been uploaded on Monday (15Feb16), had been removed from the actress' account by Tuesday afternoon (16Feb16).

Other photos of the couple admiring the Sedona mountains remained on Vanessa's profile page as WENN went to press.

The romantic getaway was a much-needed distraction for Vanessa, who lost her father Greg to cancer on 30 January (16), on the eve of her debut as bad girl Rizzo in the TV musical event Grease: Live.

Vanessa, 27, subsequently dedicated the show to her dad.

"I am so sad to say that last night my daddy, Greg passed away from stage 4 cancer," she wrote on Twitter. "Thank you to everyone who kept him in your prayers. Tonight, I do the show in his honor."

Greg was laid to rest in a Los Angeles memorial on 9 February (16).