Police are investigating a film allegedly showing a Conservative MP riding a quad bike on a public road.
The picture from Hunt Monitors shows Mr Soames with the children
A child is seen perched behind Nicholas Soames, MP for Mid Sussex. Two more children and other adults are in a trailer being towed by the quad bike.
Hunt saboteurs claim the footage was shot on New Year's Day in Slaugham, West Sussex, as Mr Soames followed the Crawley and Horsham Hunt.
A spokesman for Mr Soames said he was away and had no comment.
None of the children appear to be strapped in or to be wearing helmets in the footage.
The Police National Legal Database advises that most quad bikes are only designed for off road use.
"They do not conform to regulations in relation to tyres, lights, horn, speedometer etc. and it is therefore illegal to use them on a road," the database says.
"However, there are some road legal quad bikes and in order to be used legally on the road they must registered with the DVLA, taxed, insured and have an MOT."
A spokeswoman for Sussex Police said: "We have received pictures of a quad bike incident which are alleged to have been taken in Slaugham on 1 January and we are investigating."