Consider this: "I lost my umbrella and my wallet. My wallet was handed in at the police station. As for my umbrella, it also has been found." You could also say "it, also, has been found" to make the meaning clearer. Or "my umbrella has been found, as well" or "my umbrella has been found, also." The concept here is that there is a set of things that "have been found". The wallet is in that set. The umbrella is in that set, also. Now, in that same scenario you would be understood if you said "As for my umbrella, it has also been found" but that's arguably a bit ambiguous (and it's possibly technically incorrect). But, as I say, it would be understood in that context and it would not sound weird (unless one looked really closely at it). The reason I say it's ambiguous is that "it has also" makes it sound like this is an additional thing that you're saying about "it" rather than "it" being an additional thing that's been found. "It has also" really only belongs in sentences like this: "My umbrella has been lost and it has also been found."

This is quite clear, actually. Adverbs are placed before the main verb of the sentence. That necessarily means between the auxiliary verb ("has" in this case) and the main verb, if there's a complex tense in use (like the perfect tense in this case). This placement occurs in two conditionals especially, 1) with frequency adverbs ("often", "rarely" etc) and 2) whenever adverbs in use are short. By contrast, longer adverbs and adverbs of manner, as in most "ly" adverbs, tend to go at the end. The only reason to move the position of "also" forward, in front of the auxiliary verb, would be because you wanted to add emphasis to it. So, the correct answer, in most cases, would have to be "it has also been found".

Both, I disagree with the other commenter, I find the first to be more natural. In the first, "has been found" all stays together neatly as the verb phrase. I think the most natural way this would be said is to have also at the end, maybe change it to "too" It has been found, too.

both are correct.

Both are possible, but the second is more natural.