A police helicopter was scrambled in the hunt for a man believed to have carried out a sex attack on a cow.

Officers launched a hunt for the suspect, who was reportedly seen "committing a sexual act" on the farm animal in Hertfordshire.

The man, in his mid-20s, had been spotted interfering with a cow near Denham Way, in Maple Cross, early on Saturday morning.

But despite the ground search and help of the police helicopter, the suspect was not found.

Police are continuing to search for the man, who is believed to have carried out the attack at about 7am.

Inquiries are ongoing and witnesses are being sought.