Two men from Skegness were stopped and arrested on the A17 at Holdingham, Sleaford just after 8pm on Monday (July 28) after police were called about a silver Peugeot 206 being driven erratically, near Beckingham.
Officers found a large quantity of what appeared to be cannabis bush in the car, a police spokesman said.
The men aged 28 and 23 also had a one-year old baby with them, they added.
Social services were contacted and the men were interviewed yesterday (Tuesday, July 29) at Grantham police station.
They have since being released, on bail, pending further enquiries.