Police in London have charged a man with injecting a syringe into food products at a number of supermarkets.

       The Metropolitan Police said the 37-year-old suspect would appear in court Friday on a charge of contaminating or interfering with goods.

       A man was arrested on Wednesday on suspicion of contaminating processed meat and microwaveable products in three supermarkets in west London’s Hammersmith area.

       Police said the suspect "injected an unknown substance into a number of food and non-food products" while using "a number of needles".

       Officers say they were first alerted to reports of a man shouting abuse at people in the street.

       Local authorities have advised customers who had bought products at the stores on Wednesday evening to throw them away.

       Police said the motive was so far unknown but "there is no evidence the man was working as part of a group".