Ofcom said that it was a "time when children were particularly likely to be listening to the radio" and that the song included "prolonged sounds of sexual moaning lasting two minutes and 20 seconds".
In the report, the station said their music library was being transferred between computer systems and that "some scheduling restrictions that it had applied to songs had not been carried across to the new system".
The station said the "did not wish to offend its listeners" and confirmed a review would take place.
In response to the report, they argued other songs such as Fleetwood Mac's Big Love and Donna Summer's Love to Love You Baby also feature heavy breathing.
The station admitted children might be curious or confused by the sounds heard on the radio.
Ofcom acknowledged the "likelihood of children listening was low" given the station's target audience.
Ofcom ultimately ruled that French Kiss was "not appropriately scheduled" and breached rule 1.3 of the Broadcasting Code, which says "children must … be protected by appropriate scheduling from material that is unsuitable for them".
French Kiss was a hit in 1989 and reached number two in the UK while peaking at number one on the US dance charts.
