It's a bit of a broken process whereby an Opposition MP can ask a ministerial question, and then use that official reply to beat the minister/other government department up about something only tenuously connected. One might use the negative reply to justify an assertion that the money would have better spent on hospitals/education/protected newts/dole.
A bit like PMQs where the 1st question relates to the PM's diary and then the follow ups are an unconnected political ambush.
No wonder politicians are poorly thought of.