A US restaurant is using marijuana to sedate lobsters before killing them.

Charlotte's Legendary Lobster Pound, a restaurant in Maine, says the process is more humane as it lessens their pain before death.

Lobsters are often cooked by being dropped into a pot of boiling water, seen as cruel by some. There is growing evidence the crustaceans feel pain.

Customers at the restaurant can choose whether they want the marijuana-sedated lobster or not.

A growing body of scientific findings suggest that not only lobsters but other invertebrates, such as crayfish and crabs, are able to feel pain.

In January, Switzerland decided that lobsters must be stunned before boiling.

The owner of Charlotte's Legendary Lobster Pound, Charlotte Gill, says eating the sedated lobster will not make customers high and using marijuana leads to better quality meat, as the animal is more relaxed when it dies.

"If we're going to take a life we have a responsibility to do it as humanely as possible," Ms Gill told local newspaper Mount Desert Islander. "The difference it makes within the meat itself is unbelievable."

Marijuana is legal in Maine and Ms Gill has a license to grow and supply it for medical purposes.

Marijuana laws in the US vary from state to state. Nine states and Washington DC have legalised the drug.