Kate McCann revealed one ‘bitter’ regret she’ll have for ‘the rest of her days’ following Madeleine’s disappearance

It’s been almost 18 years since Madeleine McCann went missing while on a family holiday in Portugal, sparking one of the biggest mysteries of the 21st century.

Madeleine had been staying in an apartment in a Praia da Luz holiday complex in the Algarve with parents Gerry and Kate, as well as younger twin siblings Sean and Amelie, when she disappeared without a trace.

Her parents left the children in the apartment so that they could meet friends for dinner in a restaurant around 100 yards away, regularly checking in on the kids.

However, when Kate returned to the apartment at approximately 10pm, she found that three-year-old Madeleine was gone.

Despite a suspect who was charged with multiple sexual offences being identified, authorities are seemingly no closer to determining what happened to the toddler.

Madeleine disappeared from her Portugal holiday home in 2007 (PA)

In her 2011 memoir, Madeleine: Our Daughter’s Disappearance and the Continuing Search For Her, Kate opened up about a 'bitter regret' that she and Gerry have harboured since the night of their daughter's disappearance, sharing a small but pivotal detail.

They had requested a specific table at the Ocean Club restaurant, which would allow the group a full view of the apartment in which their kids were sleeping.

Following Madeleine's disappearance, however, Kate discovered that what had been written by the member of staff in the reservation book could have alluded to the fact that there were unsupervised children in the nearby apartment that night.

“To my horror, I saw that, no doubt in all innocence and simply to explain why she was bending the rules a bit, the receptionist had added 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,” she wrote.

Kate added: “We now bitterly regret it and will do so until the end of our days.”

The Ocean Club apartments in Praia da Luz (Jeff J Mitchell/Getty Images)

The family had booked apartment 5A Rua Dr Agostinho da Silva, an apartment which subsequently became the eye of a media storm as the world's press flocked down to report on the case.

The apartment was rented to just two further families before it was listed for sale by its owners for £250,000.

Eventually, it was purchased for less than half of the asking price, with a Brit buying the home in 2017 – 10 years after Madeleine disappeared – for £113,000.