A terminal device for use in a wireless telecommunications network, the terminal device comprising: wireless communications receiver circuitry configured to receive signals from an infrastructure equipment via a wireless access interface provided by the infrastructure equipment, position detection receiver circuitry configured to receive a radio signal from which measurements can be used to assist in determining a position of the terminal device, and controller circuitry configured to control the wireless communications receiver circuitry to detect one or more system information blocks carrying a plurality of different position assistance information transmitted from the infrastructure equipment, each different position assistance information being transmitted as one or more radio resource control layer encoded packet data units, each of the plurality of different position assistance information providing information which can be used to assist in determining the position of terminal device with a different level of accuracy, and one or more of the plurality of the different assistance information are encrypted, each of the plurality of different position assistance information are carried in a different system information block, the position assistance information carried in the plurality of system information blocks each being encrypted differently and one of the plurality of different position assistance information is unencrypted, the unencrypted position assistance information providing position assistance information for determining the position of the terminal device with the least accuracy compared with the one or more others of the plurality of different position assistance information and the unencrypted position assistance information includes an indication that the other ones of the plurality of different position assistance information are encrypted with the same encryption key or a different encryption key for each of the different position assistance information, to identify one of the plurality of different position assistance information for use by the terminal device to identify a position of the terminal device, and to estimate the position of the terminal device by combining the identified position assistance information with the radio signal received by the position detection receiver circuitry, wherein the position assistance information is identified in accordance with a permission allocated to the terminal device, and the controller circuitry configured with the wireless communications receiver circuitry to decode one or more of the encoded packet data units in accordance with a radio resource layer and to decrypt one or more of the encrypted position assistance information as a packet data convergence protocol layer in accordance with the permission allocated to the terminal device for the identified position assistance information. wireless communications receiver circuitry configured to receive signals from an infrastructure equipment via a wireless access interface provided by the infrastructure equipment, position detection receiver circuitry configured to receive a radio signal from which measurements can be used to assist in determining a position of the terminal device, and controller circuitry configured to control the wireless communications receiver circuitry to detect one or more system information blocks carrying a plurality of different position assistance information transmitted from the infrastructure equipment, each different position assistance information being transmitted as one or more radio resource control layer encoded packet data units, each of the plurality of different position assistance information providing information which can be used to assist in determining the position of terminal device with a different level of accuracy, and one or more of the plurality of the different assistance information are encrypted, each of the plurality of different position assistance information are carried in a different system information block, the position assistance information carried in the plurality of system information blocks each being encrypted differently and one of the plurality of different position assistance information is unencrypted, the unencrypted position assistance information providing position assistance information for determining the position of the terminal device with the least accuracy compared with the one or more others of the plurality of different position assistance information and the unencrypted position assistance information includes an indication that the other ones of the plurality of different position assistance information are encrypted with the same encryption key or a different encryption key for each of the different position assistance information, to identify one of the plurality of different position assistance information for use by the terminal device to identify a position of the terminal device, and to estimate the position of the terminal device by combining the identified position assistance information with the radio signal received by the position detection receiver circuitry, wherein the position assistance information is identified in accordance with a permission allocated to the terminal device, and the controller circuitry configured with the wireless communications receiver circuitry to decode one or more of the encoded packet data units in accordance with a radio resource layer and to decrypt one or more of the encrypted position assistance information as a packet data convergence protocol layer in accordance with the permission allocated to the terminal device for the identified position assistance information.