This can cover the rules of entry for visa applicants, foreign nationals or those seeking asylum at the border, detecting and apprehending those that have breached the border and removing them, or pursuing those in breach of immigration and criminal laws.
The Immigration Rules are statutory instruments laid down by Parliament under Section 3(2) of the 1971 Act which governs the regulation of entry into the United Kingdom.
The Rules are amended by Primary Legislation when required, and provide a framework to ensure that those that come to, or remain in, the UK do so legally, and those that do not can be removed.
The archetypal power of arrest is for an immigration or nationality offence, which involves a person's entitlement to be in the UK.
[5] Under Section 2 of the UK Borders Act 2007, DIOs can detain any person without arrest in a port in England, Wales or Northern Ireland if they think that the individual may be liable to arrest by a constable for any offence under Section 24 of the Police and Criminal Evidence Act 1984 or Article 26(1), (2) or (3) of the Police and Criminal Evidence (Northern Ireland) Order 1989, or if there is a warrant for their arrest.
[11] The detainee has a duty to provide the Immigration Officer with all information requested and a failure to do so constitutes an offence, punishable by 3 months imprisonment and a fine.
[13] They can arrest: A specially-trained Immigration Officer working in a Criminal Investigation Team also has the power to arrest without warrant any person that he has reasonable suspicion of committing criminal offences of obtaining or seeking to obtain leave to remain by deception, assisting unlawful immigration to a member state, helping an asylum seeker to enter the UK, and assisting entry to UK of anyone in breach of a deportation or exclusion order;[22] and also several non-immigration criminal offences such as conspiracy to defraud, bigamy, perjury, theft, obtaining services by deception, fraud, forgery and counterfeiting, trafficking for sexual exploitation, possessing and making false identity documents.
[23] An Immigration Officer can enter and search a premises owned or occupied by someone arrested for an offence without warrant for nationality documents.
[26] At all times, an Immigration Officer may arrest any person that he has a reasonable suspicion of committing an indictable offence using the "any person powers" (also known as citizen's arrest) contained in Section 24A of the Police and Criminal Evidence Act 1984.