Citing unforeseen costs, Amanda Knox and her fiance are asking for donations to their wedding following a trip to Italy in June.

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Knox and her fiance, Christopher Robinson, wrote on their registry website that their wedding funds were spent on a trip to Italy last month when she was invited to speak at a criminal justice summit hosted by the Italy Innocence Project.

The trip was Knox's first time back in Italy since being acquitted in 2015 in the murder of her roommate Meredith Kercher.

"We weren't expecting to be planning a wedding and Amanda's first ever return trip to Italy at the same time," the registry reads. "With scant time to plan, and no financial backing, we had to spend our wedding funds on this challenging and important journey."

The registry asks for donations either for specific costs or at a patron level. The patron level ranges from $500 to $10,000, with each level having a title: Stellar patron, galactic patron and temporal patron.

People can also donate to aspects of the wedding ranging from the venue, special effects, costumes and the honeymoon.

All donors will receive a signed copy of "The Cardio Tesseract," a joint book of love poems written by Knox and Robinson. The website for the book describes it as alternating love poems written in conversation with each other, "revealing the dynamics of their private life, their hopes, fears, and dark places."

Knox responded to criticism of the registry on her Twitter account.

Knox spoke at the conference on the role of the media in judicial errors. She and her former boyfriend, Raffaele Sollecito, were initially convicted in the slaying of Kercher in 2007.

Their convictions were annulled by the country's highest court in 2015 after a yearslong series of flip-flop higher-court decisions. Judges in that final ruling cited flaws in the investigation and said there was a lack of evidence to prove their wrongdoing beyond reasonable doubt, including a lack of "biological traces" connecting them to the crime.

– The Associated Press contributed to this report.