I don't have the evidence needed to form an opinion. Journalists frequently quote anonymous 'sources' which can't be checked. Some people wrongly believed that Martin Smith had changed his evidence thanks to unreliable reporting.
Here's some evidence, from a Portuguese journalist
"However, Jose Manuel Oliveira, who has covered the case since the beginning for the respected daily Diario de Noticias, said: ‘‘Who is responsible for all the information and counterinformation? It’s the police themselves.’’
Under Portuguese secrecy laws, police are forbidden from revealing details of an investigation.
Yet, as they struggle to cope with the whirlwind generated by ‘‘Caso Maddie’’, they have used a series of daily leaks to Portuguese journalists about supposed forensic evidence, diary extracts and tapped phone calls to insinuate that the couple were involved in the disappearance of their own daughter".
Link to follow.
https://www.pressreader.com/new-zealand/the-press/20070918/281921653668753