In the el mundo article the words printed are "hemos hablado de muerte por terceros no de homicidio" and Mercedes translated that spanish accurately into the english you post. But the original words spoken by Mr Amaral in the interview were portuguese IMO. It is abundantly clear from everything else that Mr Amaral says in the interview, that the original spoken portuguese was probably something similar in meaning to "we're talking about accidental death, not murder".
Firstly, thank you for confirming that the English translation is an accurate rending of the Portuguese original.
Secondly, by
English libel law, by introducing the subject of
murder, even in the way that he did, that would amount to libel.
Here is a (contrived) comparable example:
They say Fred murdered her, but I don't believe a word.
Now, assuming that the context makes clear who, exactly,
her is, and assuming that
Fred (in context) would be instantly identifiable to readers, the above statement would be construed as libel in English law if there is no definitive proof linking Fred to the murder.
However, compare this sentence by contrast:
They say Fred murdered her, but I know that's not true, because at the time of the murder, Fred was in Australia with me.
Assuming it could be proved that the person who makes the statement and Fred
were in Australia together at the time of the murder the above statement would
not be libel.
Put concisely, to repeat a libel is to be guilty of libel, unless context makes clear that the person who is the subject of the statement
cannot be misconstrued or thought of as in some way applicable to the statement made.
That is by
English law.
The point about Amaral's statement is that the first (shelved) enquiry
was a murder enquiry.
That is abundantly clear from Harrison's reports.
What I don't know is whether (by Portuguese law) the same applies.