13 42. Persons in police custody should have a formally recognised right of access to a doctor. In other words, a doctor should always be called without delay if a person requests a medical examination; police officers should not seek to filter such requests. Further, the right of access to a doctor should include the right of a person in custody to be examined, if the person concerned so wishes, by a doctor of his/her own choice (in addition to any medical examination carried out by a doctor called by the police). All medical examinations of persons in police custody must be conducted out of the hearing of law enforcement officials and, unless the doctor concerned requests otherwise in a particular case, out of the sight of such officials. It is also important that persons who are released from police custody without being brought before a judge have the right to directly request a medical examination/certificate from a recognised forensic doctor. 43. A detained person's right to have the fact of his/her detention notified to a third party should in principle be guaranteed from the very outset of police custody. Of course, the CPT recognises that the exercise of this right might have to be made subject to certain exceptions, in order to protect the legitimate interests of the police investigation. However, such exceptions should be clearly defined and strictly limited in time, and resort to them should be accompanied by appropriate safeguards (e.g. any delay in notification of custody to be recorded in writing with the reasons therefor, and to require the approval of a senior police officer unconnected with the case or a prosecutor). 44. Rights for persons deprived of their liberty will be of little value if the persons concerned are unaware of their existence. Consequently, it is imperative that persons taken into police custody are expressly informed of their rights without delay and in a language which they understand. In order to ensure that this is done, a form setting out those rights in a straightforward manner should be systematically given to persons detained by the police at the very outset of their custody. Further, the persons concerned should be asked to sign a statement attesting that they have been informed of their rights.