A person who obstructs a relevant person in the performance of anything which, by virtue of any of Parts 1 to 4 or this Part, that person is required or authorised to do commits an offence.
In proceedings against a person for an offence under subsection (1) it is a defence that he had a reasonable excuse for obstructing the relevant person.
A person who commits an offence under subsection (1) is liable on summary conviction to a fine not exceeding level 4 on the standard scale.
In this section "relevant person" means an officer of a local housing authority or any person authorised to enter premises by virtue of any of Parts 1 to 4 or section 239 or 240.