Discuss the lawfulness of the police officers' actions in scenarios (a) and (b). Where appropriate, your answers should refer to the relevant statutory provisions and the associated case law.

(a)PCs Cribb and Thackery have been sent to an address after a 999 call received from a neighbour who reported shouts and screams coming from inside the house. When they knock at the front door it is answered by Surbjit. She explains to the officers that she and her sister had an argument a little earlier but that all has calmed down now. PC Cribb asked Surbjit if the officers can just take a quick look around the house to confirm what she has said. She refuses to let them enter, declaring: "I know my rights. You can't come in here without a search warrant". Nevertheless, the officers push past Surbjit and search the house. This reveals that nobody other than Surbjit is in the house.

(b)Oleg has been arrested in the street on suspicion of drug-dealing. Immediately prior to his arrest, he was seen by the arresting officers (PCs Holmes and Watson) to leave a house. They therefore decided to search the house for evidence relating to drug-dealing. When they knocked at the front-door, Nadia answered it. She explained to the officers that although Oleg had visited her, he does not live in the house and that without a search warrant, they cannot enter. Despite her protests, PCs Holmes and Watson enter the house and carry out a search. Although they find no evidence of drug-dealing, they do seize a shotgun which they believe to be unlicensed.