The remains of the three-year-old male tiger were found strewn at two different locations near Kathotia village, about 32 km from here, on Tuesday.
Forest officials suspect the big cat might have been electrocuted by poachers.
The detainees have been identified as Hiralal, Ther Singh, Naval Singh and Kamal, while the identity of the fifth detainee is not known yet, they said, adding search for two of their accomplices is on.
The officials had last week received reports about a tiger as well as a tigress roaming with her cubs in the forest areas adjoining Kervan and Kaliasot dams, following which they set up a cage with a bait to trap the feline but their efforts proved futile.