Police are appealing for witnesses after a man and a woman were filmed apparently “engaging in a sexual act” in public.
It shows a man walking a baby in a pram yards away from the couple lying on the grass in Pingle Field. A church cemetery can be seen in the background.
The force are also investigating the source of the video.
Officers asked the public not to share the film and urged anyone who has seen it to report it online as “inappropriate content”.
“We would like to speak to anyone who was a witness to this incident,” said Detective Inspector Jon Capps, based at Banbury police station.
“This happened in daylight hours in a very public area, and we believe there were many witnesses to this offence who have yet to come forward to police.
“We would also like to speak to the person who filmed the incident to assist with this investigation.
“Incidents of this nature are rare but we would like to remind and encourage anyone who witnesses incidents of this nature to report it to the Police.”
It is believed the offence took place at some point on 11 May. The film was published online by The Sun on Friday night.