Trading Standards officers are targeting an Asian chewing tobacco which leaves “unsightly” stains on the streets.

Paan, a mixture of nuts and spices wrapped in a leaf, is known to be sold on Green Street, Upton Park, where it is popular among members of the Asian community.

Newham Council said that shopkeepers have evaded paying duty on the tobacco and UK standard health warnings are often missing, meaning the sellers face prosecution if they sell it illegally.

Last year, around 10,000 packets of paan were seized as part of an ongoing series of raids by the borough’s Trading Standards officers and the council’s Street Scene Enforcement team.

Users often spit on the pavement while chewing paan, leaving a dark-red stain, and the substance has been linked to mouth and oesophageal cancer.

Cllr Unmesh Desai, executive member for crime and anti-social behaviour, said: “Paan staining is unsightly and expensive to clean.

“Users are risking their health - and even their lives.”

Shoppers who spot shops selling paan illegally are asked to report it to Consumer Direct on 01622 626520 or www.consumerdirect.gov.uk.