The 6 unanswered questions we have after watching The Disappearance of Madeleine McCann.

Madeleine McCann was just three years old when she disappeared in 2007.

The toddler was holidaying with her family in Portugal when she went missing, while her parents were dining at a nearby restaurant.

There has never been a credible sighting of her since.

At around 10.00pm on May 3, 2007, British doctor and mum-of-three Kate McCann left a local tapas bar and walked the 83 metres back to her holiday apartment to check on her sleeping children.

The Disappearance of Madeleine McCann trailer. Post continues after video.

Kate, her husband Gerry, their three-year-old daughter Madeleine, and their two-year-old twins Sean and Amelia, had travelled to the area from Leicester, England, for a family holiday.

When Kate arrived at apartment 5A she immediately felt that something wasn’t right.

The door to the children’s room was further open than she had left it. When she looked in the room she saw Madeleine’s bed was empty. A gust of wind then blew into the room, revealing the open window and window shutters on the wall opposite Maddie’s bed.

Kate ran back to the tapas bar to where Gerry was dining with the seven friends they had travelled with, the group that would later become known as the Tapas 7.

She screamed: “They’ve taken her.”

The group quickly began searching the apartment and the surrounding area but there was no sign of Maddie. The McCanns then reported the toddler as missing.

In the following days, Portuguese, British and international press flocked to the seaside village. The story of the disappearance of a blonde-haired toddler in what was considered to be a safe family holiday hot spot was splashed across newspapers around the globe. It became one of the most sensationalised news stories of the 21st century.

For the past 11 years Portuguese police, Scotland Yard, and Maddie’s parents have worked tirelessly trying to figure out what happened to the young girl. But so far, they have no answers.

Two weeks ago a documentary called The Disappearance of Madeleine McCann dropped on Netflix. Although the eight-part documentary was the most comprehensive recap of the case to date, it still left us with a lot of unanswered questions.

Here are the six unanswered questions we have after watching the Netflix documentary:

Why were the McCann children crying the night before?

The day Madeleine disappeared she asked her mum, “Why didn’t you come when Sean and I cried last night?”

Looking back, Kate says that comment has always haunted her.

“We were puzzled,” she wrote in her book Madeleine: Our daughter’s disappearance and the continuing search for her.

“Did she mean when they were having a bath? Or just after they’d gone to bed?”

Kate had been in the children’s room the night before, she’d made the decision to sleep apart from her husband.

“It certainly hadn’t been in the early hours, because I’d been in the room with them, even closer than usual,” she continued.

“Gerry and I were disconcerted. Could Madeleine and Sean have woken up while they were at dinner? If so, it was worrying, obviously, but it didn’t seem probable,” she wrote.

Because neither Kate nor Sean took part in the documentary, we still have no clarity around what Madeleine meant by that comment.

Why did the Tapas 7 say they saw Robert Murat when they didn't?

Several members of the Tapas 7 said they had seen Robert Murat hanging around apartment 5A in the hours after Maddie was reported as missing.

Murat said he was at his house all night and didn't know about the disappearance until early the next morning. He was later cleared of having any connection to Maddie's disappearance.

If Murat wasn't there, why did the Tapas 7 say he was? Why were they so keen to point the finger at him?

Whose blood did the sniffer dogs pick up?

The Disappearance of Madeleine McCann looks at how sniffer dogs used in the case allegedly detected the scent of blood, and a human body, in the McCann's apartment and in their hire car.

While the McCanns were eventually cleared of any involvement in their daughter's disappearance, the sniffer dog evidence was never explained.

Whose blood was in the apartment and the hire car? Had there really been a body in the car?

If the McCanns hired the car weeks after Maddie disappeared, who had it before them?

What really happened to Joana Cipriano?

The documentary also looks at the case of Joana Cipriano, a local Portuguese girl who went missing before Madeleine.

The girl's mother, Leonor Cipriano, and uncle, Joao Cipriano, were eventually charged with her murder. Police alleged the pair had murdered her after she had witnessed them having incestuous sex.

They also alleged they dismembered her body and placed it in a freezer before disposing of it.

The police were able to charge the pair after Joao confessed. However, she later came out and said she was beaten and coerced into giving her confession.

If Joana wasn't murdered by her mother and her uncle, what happened to her? Could her case actually be linked to Madeleine's?

Why didn't the twins wake up?

Madeleine's younger twin siblings, Sean and Amelia, slept through the night on the day she disappeared.

Even when the McCann's friends and police were walking in and out of the room during the night while they were trying to find out what happened to Madeleine.

Were the twins drugged either by the McCanns to help them sleep, or by a predator who wanted to keep them quiet?

Who was the Australian woman in Barcelona?

In the documentary, a man recalls being in Barcelona on the night Madeleine disappeared.

He said he was walking along a street when a woman approached him. The man says the woman spoke English, with possibly an Australian accent, and asked him, "Do you have the girl? Do you have my new daughter for me?".

When it became obvious to her that he had no idea what she was talking about, she quickly walked away.

If this is true - who was the Australian woman? Could Madeleine be with her? Could Madeleine actually be living in Australia? Could this be linked to cases of other missing children?

For more stories on Madeleine McCann, you can read more here:

• The 7 most compelling theories about what happened to Madeleine McCann.
• Inside the sex trafficking theory linked to Madeleine McCann's disappearance.
• What the Madeleine McCann documentary didn't include.
• What we know about the little known twin siblings of Madeleine McCann.
• The horror discovery about Madeleine's disappearance that still haunts Kate McCann.