6.  The applicant was born in 1952 and lives in Cologne. He works as a criminal defence lawyer. 7.  In 2009 the applicant defended a client in criminal proceedings. After the proceedings had concluded, and when the client had already been imprisoned, the client’s fiancée transferred the applicant’s legal fees (1,500 euros (EUR)) from her private bank account to the applicant’s professional account. The subject of the bank transfer read: “Prof Dr Sommer fees (client’s last name)”. 8.  In 2010 and 2011 the Bochum public prosecution office conducted investigations into several individuals suspected of having committed fraud on a commercial basis as members of a gang. One of the suspects was the aforementioned applicant’s former client, who again retained the applicant as his defence lawyer. During these investigations, the bank accounts of several people, including the applicant’s client and the client’s fiancée, were inspected. The inspection revealed that the client’s fiancée had received money (EUR 7,400) which was suspected to have stemmed from illegal activities, and had transferred EUR 1,500 for legal fees to the applicant’s bank account. 9.  On the basis of the bank transfer of fees from the fiancée to the applicant in relation to the first set of criminal proceedings, the Bochum public prosecution office also contacted the applicant’s bank. On 1 March 2011 the public prosecutor asked for a list of all transactions concerning the applicant’s bank account from 1 January 2009 until that day. He asked the bank not to reveal the request to the applicant. He based his request for information on Articles 161a, 51 and 70 of the Code of Criminal Procedure (hereinafter “the CCP”), in conjunction with Article 95 of that Code (see paragraphs 23‑25 below). 10.  On 1 April 2011 the public prosecutor requested further information and asked the following questions:
“(a)  Which other bank accounts, investment accounts or safe deposit boxes at your bank belong to the person in question?
(b)  What rights of disposal (Verfügungsberechtigungen) does the person in question have?
(c)  Who else has a right of disposal?
(d)  Do other accounts exist of which the person in question is the beneficiary?
(e)  If so, what are the current balances on these accounts?
(f)  If bank accounts have been closed by the person in question, please submit information about the date of closure and the balance at the time of closure, and where the money was transferred after closure.
(g)  Which addresses of the person in question are known to you?
(h)  Are you aware of any money transfers to or other transactions with foreign countries? If so, please specify the bank, account and amount of each transfer or transaction.
(i)  Please submit a list of all transactions for all existing or closed accounts from 1 January 2009 onwards.
(j)  Are there any credit cards connected to any of the accounts?” 11.  The bank complied with both requests for information and submitted the information to the public prosecution office. In both instances, the public prosecutor did not order the bank to submit the information, but pointed to the obligations of witnesses set out in the CCP and the possible consequences of non‑compliance (see paragraph 23 below). 12.  The information received was analysed by the police and the public prosecutor, and a list of fifty-three transactions deemed to be relevant was included in the investigation file as evidence. Therefore, everyone who had access to the case file, such as the lawyers of the co‑accused, also had access to the applicant’s banking information, including the names of his clients who had transferred fees. 13.  On 31 January 2012, after several unsuccessful requests, the applicant, as the lawyer of the accused, was granted access to the investigation file. From the case file he learned, for the first time, of the investigative measures concerning his own bank account. 14.  On 24 April 2012 the applicant asked the Chief Public Prosecutor to hand over to him all data received from the bank and destroy all related data at the public prosecution office. In his request the applicant emphasised his role as a criminal defence lawyer, which was known to the acting public prosecutor, and the consequences for his clients, whose names were accessible through the banking information. He further argued that the investigative measures lacked a legal basis. 15.  On 2 May 2012 the Bochum Chief Public Prosecutor refused the applicant’s request. He stated that there was a suspicion that the money transferred from the client’s fiancée stemmed from illegal activities. Consequently, it was legitimate for the public prosecutor to investigate whether further money transfers had taken place between the applicant and his client or the client’s fiancée. Therefore, since the investigative measures were legitimate, the information received had to be kept in the investigation file. The Chief Public Prosecutor further pointed out that there was no legal basis for returning the data or taking the documents out of the investigation file. The Chief Public Prosecutor cited Article 161 of the CCP (see paragraph 22 below) as a legal basis for the information requests, since the bank in question was a bank under public law and therefore considered to be an authority. 16.  Subsequently, the file was transferred to the Bochum Regional Court (“the Regional Court”), because the criminal proceedings against the applicant’s client had started. The applicant therefore asked the Regional Court to return the data. 17.  On 19 July 2012 the Regional Court refused the applicant’s application. The court found that the investigation was lawful, that the bank had provided the information voluntarily, that the documents could therefore only be returned to the bank and not to the applicant, and that the prohibition of seizure under Article 97 of the CCP (see paragraph 28 below) was not applicable, since the information had not been in the applicant’s possession. Nonetheless, in order to safeguard the client‑lawyer privilege, it also decided to separate the documents in question from the general court file and only grant access to them if reasons proving sufficient interest were provided. 18.  The applicant appealed against the decision. He challenged in particular the findings that the bank had acted voluntarily and that there had been sufficient suspicion for such an extensive analysis of his banking transactions. He further reiterated that, owing to his position as a lawyer, there were several safeguards in place concerning the seizure of documents (see paragraphs 26-29 below), and these should not have been circumvented because his and his clients’ personal information was stored at and by the bank, and not at his office. 19.  On 13 September 2012 the Hamm Court of Appeal confirmed the decision of the Regional Court. It found that the decision was proportionate and that the safeguards were not applicable, in particular since the bank could not be considered a person assisting the applicant or a person involved in the professional activities of the applicant under Article 53a of the CCP (see paragraph 27 below). 20.  On 19 September 2013 the Federal Constitutional Court refused to admit the applicant’s constitutional complaint, without providing reasons (case no. 2 BvR 2268/12).