Former socialist party leader and current MEP Sergey Stanishev will not be tried over the seven secret documents he allegedly lost while he was Prime Minister, magistrates say.

The reason is that Stanishev enjoys immunity as member of the European Parliament.

Stanishev, who was Bulgaria's Prime Minister (2005-2009) and is to serve as MEP for some weeks, is accused of having lost seven secret documents from Bulgarian institutions and NATO which were confided to him while he was in office.

His five-year term will end in 2019, after the seven-year prescription of his act has expired.

Prosecutors have not yet commented whether a request will be made to lift Stanishev's immunity.

The case misfired two times after he consecutively failed to receive the indictment.

Stanishev is at the same time unable to obtain the document, since it is marked "Secret", and only the prosecuting authority which labeled it that can  remove it as well.

The fate of seven secret reports has remained a mystery since 2010.

Three of the documents were produced by the state security agency DANS, two by the Interior Ministry, one by the Defense Minister and by NATO officials. They were handed to Stanishev personally, and the prosecution argues he lost them between November 4, 2005 and September 10, 2009 (he was Bulgaria's Prime Minister until July 2009).

In mid-November 2011, the Sofia City Court opened the administrative case against the socialist leader. The indictment was submitted to the court more than a year after he was officially charged amid lots of media fuss.

Sergey Stanishev was Bulgaria's Prime Minister between 2005 and 2009, leading the so-called "three-way coalition". He also presided over the Bulgarian Socialist Party (BSP) from 2001 to 2014, when Mihail Mikov took over.