For over a decade, police have been attempting to find information pertaining to Madeleine McCann's whereabouts following her May 3, 2007, disappearance from her parents' hotel room in Praia da Luz, Portugal. Throughout the subsequent years, her parents, Kate and Gerry McCann, have worked with law enforcement as they have tried to find answers.

In recent weeks, new details have emerged about Christian Brückner, who has since become the prime suspect surrounding McCann's disappearance, including the fact that he may have been "tipped off."

According to Sky News, a report from Correio de Manha, a newspaper in Portgual, indicated that the 43-year-old may have been alerted by a hotel worker that McCann, then 3, was not being supervised on the night of her 2007 disappearance. As stated by the publication, a "crooked hotel worker and an innocent receptionist" allegedly could have informed Brückner that he would have the "opportunity to break into her family's holiday apartment."

READ: Madeleine McCann Update: Prime Suspect Previously 'Freaked Out' When Co-Workers Mentioned Her Name

According to the report, prior to McCann's abduction "Christian B" learned about Kate and Gerry's whereabouts that evening due to a noted dinner reservation that was made by an employee of the Ocean Club, the resort where the family had been staying in Praia da Luz. 

This was a theory that Kate had previously considered in her 2011 book, "Madeleine: Our Daughter's Disappearance and the Continuing Search for Her." In the work, she discussed the realization that the unintentional action could have played an important role in what took place.

"It wasn't until a year later, when I was combing through the Portuguese files, that I discovered that the note requesting our block booking was written in a staff message book, which sat on a desk at the pool reception for most of the day," she wrote, adding, "To my horror I saw that, no doubt in all innocence and to explain why she was bending the rules a bit, the receptionist had written the reason for our request... we wanted to eat close to our apartments as we were leaving our young children alone there and checking on them intermittently."

READ: Madeleine McCann Update: Prime Suspect's Past May Link Him To Another Missing Girl

As for how the information could have been passed along to Brückner, the employee, who has since reportedly been identified, allegedly had the suspect's number stored in his mobile phone.  

"Did he learn from somebody who was complicit, not necessarily at all in abducting or murdering Madeleine, but perhaps in how to take advantage of people being away to rob an apartment?" asked Anthony Summers, co-author with Robbyn Swan of the book "Looking For Madeleine."

Moving forward, McCann's case, which was once believed to be "unsolvable," could potentially be aided by information from unexpected people who may have "concrete knowledge."

Madeleine McCann Madeleine McCann disappeared on holiday in Praia da Luz, Portugal, on May 3, 2007. Photo: METROPOLITAN POLICE/Handout