100 Legal Digest of International Fair Trial Rights of coercion or oppression in defiance of the will of the accused”.404 If, however, a defendant voluntarily decides to give evidence as a witness in her/his own case, s/he will be subject to cross-examination by the prosecution (See also 6.7.3). The right to remain silent is not confined to the trial but also applies to the investigation stage. A suspect or accused has the right to remain silent under police questioning.405 5.2.2 Compulsion to produce, or allow collection of, material evidence The privilege against self-incrimination is concerned with respecting the right to silence. This means that it does not extend to preventing the use in criminal proceedings of material that can be obtained from an accused person through the use of compulsory powers that do not affect the accused’s right to silence. This might include, for example, documents obtained under a search warrant, or breath, blood and urine samples, or bodily tissue compulsorily obtained for the purpose of DNA testing, so long as this is done pursuant to a requirement in the law and to the extent necessary and proportionate to combat crime.406 In P.G. and J.H. v the United Kingdom, the European Court of Human Rights referred to voice samples, which did not include any incriminating statements, as akin to blood, hair or other physical or objective specimens used in forensic analysis, to which privilege against self-incrimination does not apply.407A failure to comply with such requirements may itself amount to an offence or to contempt of court (See also 3.5). A different situation occurs when a suspect or accused is compelled to actively provide evidence, such as documents, by way of locating, obtaining, delivering or giving otherwise access to them, thus contributing to her/his conviction. In Funke v France, the European Court dealt with a custom case in which a conviction was ordered as a way of pressuring Mr. Funke to provide documents constituting evidence of offences he had allegedly committed. The Court noted that the special features of customs law cannot justify such an infringement of the right of anyone charged with a criminal offence to remain silent and not to contribute to incriminating her/himself.408 5.2.3 Legal compulsion to answer questions In limited circumstances, authorities may have the ability to compel a person to answer questions outside the context of a criminal hearing. This may be by way of a court hearing held before a judicial officer, or by questions asked in other settings by a non-judicial officer, and commonly involves the giving and recording of evidence under oath. Wherever this occurs, the privilege against self-incrimination demands that the evidence provided cannot be used in subsequent criminal proceedings against the person compelled to give 404 Saunders v the United Kingdom [1996] ECHR 65, para 68; Heaney and McGuinness v Ireland [2000] ECHR 684, paras 54–55; and Allan v the United Kingdom [2002] ECHR 702, para 44. 405 John Murray v the United Kingdom [1996] ECHR 3, para 45. 406 Saunders v the United Kingdom [1996] ECHR 65, para 69. 407 P. G. and J. H. v the United Kingdom [2001] ECHR 550, para 80. 408 Funke v France [1993] ECHR 7, para 44.