should I tell my boss or upper managers?

My team has one indian gal one indian guy. The guys is one level above me and the indian gal. He is very lazy and is not that good. every day only works for about 2 hours. most of time, he is on internet or doing his part time MBA. he only stays in office for about 6-7 hours. the gal is very smart. she is doing her PHD and spending about 1 hour working only. she stays in office for about 5-6 hours each day.

My manager is in another city does not know all these kinds of things. Both of them help each other to cheat. I asked one of the other managers if the upper level knows that or not. she told me "No".

I really want my boss knows. every year, only one person can get an excellet review. I got it two years in the row. now my boss told me, he needs to give others a chance too.

should i tell my manager? or should i do anything?