Depends wholly on the circumstance of course but generally to a detective who is interviewing someone under caution, a refusal to answer some very basic questions will be taken as a hostile response and a sign that not all is as it should be.
And here is the nub of the problem.
This is not a nice friendly chat between mates - this is an interview as a part of a criminal investigation. It is
already hostile. The detective
already thinks not all is as should be.
In the UK, the interview will be under caution, in Portugal under Arguido status. Both of these give a right to silence. The standard advice is to use it.
As George Bruch made clear in the video I provided a link to put it - "imagine you are at a fairground - there is an ex professional boxer in a ring. His promoter is offering £1000 cash if you can survive a 3 minute round - this is what you are getting into in a police interview and thinking you can win".
The detective is a pro - you are a frightened amateur. Even if innocent you may find yourself in serious trouble, especially with an investigating team wanting a conviction.