They were arrested 2 weeks ago near Cullompton
A man and a woman, who reportedly had sex on a National Express service as it travelled along the M5 will face no further action.
A 29 year old man from Bristol and a 32 year old woman from Barnstaple, were arrested on suspicion of an act of outraging public decency.
Now Devon and Cornwall Police say CCTV from the bus was "inconclusive".
Lifeboat washes up at Sidmouth
Torbay hotels tested on child exploitation checks
Rare wolf pups born at Devon Zoo
“Disappointment” over North Devon funding settlement
Controversial Exeter road consultation to begin in the New Year
Family homes to replace former Plymouth language school
