If somebody is suspected of a criminal offence the prosecutor's office and the police may take the measures which are necessary to establish his identity. The suspect may be kept in custody, if the identity cannot be established by other means or only with considerable difficulty. Under the prerequisites of the second sentence, it shall be admissible to search the suspect and the objects found on him as well as to carry out measures for identification purposes.
If and so far as this is necessary to clear up a criminal offence, the identity of a person who is not suspected of an offence may also be established.