I (have) just finished it five minutes ago.

[z7655431]

A: Have you finished the term report yet?
B: No. How about you?
A: Yeah. I have already finished it. Actually, I (have) just finished it five minutes ago.
-In the final sentence, what verb tense should I use?

 

[Matthew Wai]

'You CANNOT use the Present Perfect with specific time expressions such as: yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc.' (My emphasis.)── quoted from http://www.englishpage.com/verbpage/presentperfect.html

Having read the above, I think the simple past 'finished' is correct.

 

[Tdol]

I'd use the following:

Actually, I just finished it five minutes ago.
or
Actually, I finished it just five minutes ago.