There has been discussion about duplicate questions in different languages (1, 2, 3). The consensus was that, if two questions are the same but in different languages (Spanish and English in our case), one should be marked as a duplicate of the other.
The policy on the language of answers is to prefer answering in the same language as the question, but to also allow answers in the other language.
However, I have not found any discussion on duplicate answers in different languages. It happens sometimes that a user answers a question in one language, and another user adds another answer with the same information in the other language (maybe even a direct translation). This can be helpful to users that are not fluent in one of the two languages, but it has sometimes caused complaints from the first answerer saying that the second answer does not add any new information.
So should we accept answers with the same information in different languages?