A local resident tipped off police and the force helicopter was scrambled to the scene at the Byes in Sidmouth, Devon, on Monday evening.
The resident claimed a foursome were engaging in sexual activity and one of the four suspects was wearing handcuffs.
The four managed to give the police the slip and the Devon and Cornwall force chopper was sent out from its Exeter base to track down the offenders.
The alleged indecency involved two men and two women at around 6.20pm.
The aircraft hovered overhead and later police arrested a 20 year old man from Sidmouth and a 28 year old man from Plymouth, Devon.
They were arrested on suspicion of escaping lawful custody and committing an act outraging public decency.
A female from Exeter was also arrested but no action will be taken against her. Both men were bailed until next month.