17.This section confers a power of entry and inspection, in order to enable the gathering of evidence, and a power to enter premises to carry out a forfeiture order.
18.Subsection (5) creates an offence of intentionally obstructing or delaying any person in the exercise of either power of entry.  This again is a summary offence for which the maximum penalty is a fine not exceeding level 3 on the standard scale (currently £1000) (subsection (6)).
Commentary on Sections Section 4: Powers of entry