Officers from West Yorkshire Police roads policing unit were shocked after pulling over a van and finding a baby in a pushchair in the back.
Officers tweeted late on Saturday night (July 13) after making the stop and finding the "very young child asleep".
The @WYP_RU account tweeted: "M1 South. Vehicle followed into @syptweet area due to manner of driving by @WYP_MarkJessop
"With the assistance of other units vehicle was stopped!
"We were not happy when we looked in the rear.
"Driver dealt with accordingly. #OperationalSupport #Team3 #Fatal4"
A disturbing picture shows the pushchair and baby in the rear of the van.
The unit later tweeted: "In the rear, to our shock was a pushchair, with a very young child asleep.
"The onward journey was safe once we had made alternative arrangements for them."
The force made alternative arrangements for the occupants of the van and dealt with the driver "accordingly". Daniel.Sheridan@jpress.co.uk