Detectives had such concerns over what transpired the night Madeleine McCann disappeared that they were desperate to reconstruct movements of key people, including Kate and Gerry.

Replicating actions of the McCanns and their group of friends known as the Tapas 7 would help clarify "extremely important details" and timelines, according to the police case files.

It was a reconstruction that the McCanns appeared reluctant to participate in - despite Portugal's police pleading its importance - and it was eventually aborted.

Less than two months after a significant effort to set up the reconstruction had floundered, police shelved the investigation in July 2008.

The reconstruction that never happened caused "damage" to the McCanns, according to a final 17-page report on the 14-month long investigation.

Portugal's Public Prosecutor stated in the report that the McCanns "lost the possibility to prove what they have protested since they were constituted 'arguidos' (a formal suspect): their innocence towards the fateful event."

Planning for the failed reconstruction began in earnest around April 2008, almost one year after Maddie vanished on May 3, 2007 from her family's holiday apartment in Praia da Luz.

A series of emails between Portugal's police and Leicestershire police shows the protracted and ultimately futile negotiations to convince Kate and Gerry's seven UK-based friends to come back to Praia da Luz for a reconstruction.

At this time, the McCanns were also home in the United Kingdom, having returned to England two days after they were put under 'arguidos' status.

On May 1, 2008, doctors Kate and Gerry McCann appeared on both BBC and Sky News to tackle the looming reconstruction issue, after news of a potential re-enactment began to appear in the media.

Gerry was worried about a potential press frenzy in Portugal, and rightfully pointed out the decision was not just theirs to make, but also the responsibility of the Tapas 7.

"I think also the other issue is how much more information will that get us one year on? We have told everything to police," Gerry said to BBC host Bill Turnbull during a studio interview.

"We will do anything if we believe it will help to find Madeleine," Kate added, despite having declined to answer 48 questions during a police interview on the day she was made an 'arguido'.

Privately, police had always harboured doubts over the witness statement of Jane Tanner, one of the Tapas 7.

Tanner's testimony, in which she claimed to see a man carrying a child near the apartment about 9.15pm the night Maddie went missing, was pivotal in driving the McCann's abduction theory.

Detectives had highlighted her statements, which had changed during subsequent police interviews, as one of the primary reasons for a reconstruction. There had also been a lack of forensic evidence to indicate an abduction.

US criminal profiler Pat Brown, who has studied the case extensively, including visiting Praia da Luz, told Nine.com.au she had problems believing Tanner's account.

"I've been on that street [where the alleged sighting of a man carrying a child occurred] and what Jane Tanner says does not make sense," Brown said.

"If Jane Tanner was telling the truth, then Gerry McCann has an alibi."

As negotiations for the reconstruction rumbled on, members of the Tapas 7 relayed a number of concerns to Leicestershire Police, questioning the motives of Portugal's investigation.

The Policia Judiciaria responded with assurances around security, detailing that the Tapas 7 could bring their lawyers, and that no images or video would be released to media.

In the middle of May 2008, with Maddie still missing more than one year on, it became clear that the Tapas 7 were refusing to travel to Praia da Luz for the re-enactment.

Kate and Gerry McCann responded to Portugal's police stating they would participate but, without the Tapas 7, the reconstruction was already null and void.