POLICE are warning people against entering a field of hemp which thieves are confusing for cannabis.

Kidderminster Police spokeswoman Joanne Hammond said it was important people realised hemp was being grown legally - to stop thieves stealing and smoking it.

She added one man had already been arrested for stealing the plants, which are being grown for controlled drugs at an unspecified location.

Inspector Jim Baker said police had received calls from members of the public concerned cannabis was being grown in the field.

"I want to reassure people that this plant is being grown legally and under licence," he said.

"Because it can be confused with cannabis it appears that some people have been helping themselves to the plant.

"It is not cannabis, if smoked it will have no effect and cause no harm."

He added police would be patrolling the area and take action against people caught.