A sampling tool (100, 200) for use in obtaining a sample of material from within a container comprises a cutter shaft carrying a cutting head (1, 101), the shaft including a passage which has an inlet located at or towards the cutting head (1, 101), a drive mechanism which is adapted to cause the cutter shaft to rotate in a first direction in turn to cause the cutting head to cut a hole in wall of the container and expose the inlet to the material contained within the container, a flexible seal (3, 103) carried by the cutter shaft which is located so that with the inlet in contact with the fluid the seal extends at least partially through the hole, a clamp mechanism which is operable once the seal is located in the hole such that continued rotation of the cutter shaft pulls the cutting head (1, 101) back towards the hole to mechanically clamp the seal (3, 103) around the hole; and a self sealing connector which is in connection with an outlet of the passage and through which a sample may be withdrawn into a suitable receptacle by drawing it through the passage.