A group of people in dressing gowns in a dozen caravans are said to have pitched up at a Tesco car park in north west London.
The group, believed to be travellers, were reportedly blocking parking spaces around the supermarket with more than a dozen caravans.
The local council had been notified of the situation at the Wembley Tesco Extra supermarket, the Mail Online reports.
The group's caravans, mobiles homes and other vehicles blocked car park entry routes and straddled multiple parking spaces, according to reports.
It is understood the travellers were at the site last Thursday.
They are believed to have arrived in the morning and left by the afternoon, without causing a disturbance.
Photos show at least 12 caravans dotted around the Tesco car park, which is less than a mile from the major Wembley Park stadium.
The Mail reports another Tesco supermarket was closed down when police were called over travellers last week.
The Tesco in New Malden was closed down temporarily as a safety precaution, the Mail reported.
Brent Council operates council-owned pitches to accommodate travellers nearby.
The Mail reports there is no suggestion the two incidents are linked, nor that the nearby travellers' site is linked to this group.
Brent Council said that as the Tesco car park is private land.
A spokesman said: "This is a matter for the landowner and the police."
The Met Police said they were not involved.
Tesco was contacted for comment.