Noise from engine bay

My mates r27 is making a strange noise. After it starts to warm up there seems to be this intermitent whining noise from the front of the engine bay when its warming up. Its coverd 43000 miles and is on a 57 plate. It drives fine just has this odd whining noise. Has anybodyhad anything like this or suggest what it could be?
 
thats what i have a clue it could be but not 100m sure, as its nearly 5 yrs old i was thinking could be
 
Our 200 has always had a whine from the engine bay when you start it up for bout 5 mins (If you leave it idling). Its definately the belt but isnt an actual problem.
 
Our 200 has always had a whine from the engine bay when you start it up for bout 5 mins (If you leave it idling). Its definately the belt but isnt an actual problem.

im guessing it will get worse in the cold/winter weather aswell due to it taking longer to warm up?