At least nine children were killed and about 20 injured when the speeding vehicle lost control and ploughed through them outside a government school building on the outskirts of Muzaffarpur on Saturday.
"Manoj Baitha, a district level worker of Sitamarhi, has been suspended from the primary membership of the party for a period of six years," BJP's Bihar unit vice-president Devesh Kumar said.
Muzaffarpur district president Subodh Singh has sent a communication to this effect to the party's state headquarters here, Mr Kumar told PTI.
About reports that a banner fixed on that vehicle described Mr Baitha's designation in the party as state secretary general of Mahadalit Prakoshth, Mr Kumar said, "No such post exists in the organisation. The worker appears to have fabricated it."
Bihar Deputy Chief Minister Sushil Kumar Modi has said the police were directed to take "sternest possible action" against Mr Baitha irrespective of his political affiliations.
The opposition RJD has accused the Nitish Kumar government of trying to shield Mr Baitha and alleged that the BJP worker was "drunk" while behind the steering wheel even though sale and consumption of alcohol is banned in the state.