This section applies to—
any indictable offence under the 1949 Act; and
any offence under section 1(1) of that Act other than one consisting in the installation or use, otherwise than under and in accordance with a wireless telegraphy licence, of any apparatus not designed or adapted for emission (as opposed to reception).
A constable may arrest without warrant a person who has committed, or whom the constable with reasonable cause suspects to have committed, an offence to which this section applies, if the name and address of that person are unknown to, and cannot be ascertained by, the constable or the constable has reasonable grounds for doubting—
whether a name and address furnished by that person as his name and address are his real name and address; or
whether that person will be at an address furnished by him for a sufficiently long period for it to be possible to serve him with a summons.
The preceding provisions of this section do not apply to Scotland.
This section shall not prejudice any power of arrest conferred by law apart from this section.