The incident occurred during crew change via helicopter.
During routine helicopter operations a helideck assistant (HDA) picked up a case containing a water testing kit whilst back loading cargo onto the Helicopter. This cargo was not destined for the Helicopter and as such was not on the manifest. The heliport was advised of the error after the helicopter had left. It was later discovered that a small vial of liquid containing ethanol (15ml) was inside the case.
Cargo for dispatch onto helicopter should be kept separate form all other items onboard.
All cargo for the flight must be labelled. Where possible this should include flight number and name.
Helideck landing officers (HLOs) should issue clear instructions to helideck assistant prior to flights regarding manifested cargo.