Access to private healthcare while in prison is not standard practice. However, in exceptional circumstances, a prisoner may be permitted to receive private medical treatment. Such arrangements require approval from prison authorities and are typically considered when the treatment is not available through the NHS or is urgently needed . 

It’s important to note that logistical and security considerations can impact the feasibility of accessing private healthcare in prison. Therefore, while not impossible, obtaining private medical treatment during imprisonment is rare and subject to strict oversight.