In Austria there’s the Volksanwaltschaft (roughly translates to "lawyers for the people", official English name "The Austrian Ombudsman Board"), which consists of three lawyers who are selected by the National Council for six years. They cannot be voted out, recalled or removed from office. The ombudspersons are sworn in by the Federal President.
You can fill a complaint there if you feel you have been treated unfairly. Your case is then reviewed and appropriate actions will be taken if necessary.
The Volksanwaltschaft is embodied in the Austrian Federal Constitution:
Article 148a. (1) Everyone can lodge complaint with the Ombudsman Board (Commission for Complaints from the Public) against alleged maladministration by the Federation, [...] mainly for alleged violation of human rights [...]. All such complaints must be investigated by the Ombudsman Board. [...]
Their task is to scrutinise the public authorities and ensure the observance of the human rights.
To ensure the observance of human rights, the Volksanwaltschaft has many entitlements, including the right to visit any place where imprisonment may take place and take a look at files.
Note, however, that the Volksanwaltschaft primarily issues recommendations:
Article 148c. The Ombudsman Board can issue to the authorities [...] recommendations on measures to be taken in or by reason of a particular case. [...] [T]he authority concerned must within a deadline to be settled by federal law either conform to the recommendations [...] or state in writing why the recommendations have not been complied with. The Ombudsman board may in a specific case at the occasion of a certain case request a deadline to cure the delay by a court (Art. 148a para 4) and suggest measures of supervisory control.
Furthermore, there’s a television programme aired by the national broadcasting service ORF which reports about the cases dealt with by the Volksanwälte (the lawyers), who also come to the studio to comment on the case. (The latest issue can be found online.)
There’s an official English website where you can learn more about the Volksanwaltschaft.
Constitution translations were taken from here.