Police are investigating after footage emerged on social media of a naked man wearing a black mask and trainers walking down the street at night.
The video, which has been shared widely online, is understood to have been filmed in Lytham, Lancashire.
It shows the man wearing only the mask and a pair of black‑and‑white trainers as he walks along a row of residential homes.
Lancashire Police said the incident took place at about 12.50am on July 18 in the area of Westby Street, Cleveland Road and Bannister Street, despite claims on Facebook it happened later in the month.
A spokesman said: “We are aware of a concerning video circulating on social media of a naked male wearing a face covering walking around Lytham in the early hours of the morning.
“This incident was not initially reported to police and has only been brought to our attention after it has been viewed on Facebook.
“Fylde Rural Task Force are currently conducting CCTV and house‑to‑house inquiries and would like to reassure you that we are taking this matter seriously.”
Officers urged anyone with information or relevant CCTV to contact FyldeRTF@lancashire.police.uk.
