Berlin: An award-winning journalist who worked for Der Spiegel, one of Germany's leading news outlets, has left the weekly magazine after evidence emerged that he committed journalistic fraud "on a grand scale" over a number of years, the publication said on Wednesday.

Spiegel published a lengthy report on its website after conducting an initial internal probe of the work of Claas Relotius, 33, a staff writer known for vivid investigative stories. The magazine said Relotius resigned on Monday after admitting some of his articles included made-up material from interviews that never happened.

Claas Hendrik Relotius, an award-winning German journalist, resigned from Der Spiegel because of "journalistic fraud". Credit:Facebook

The Hamburg-based magazine said Relotius contributed almost 60 articles published in print or online since 2011, first as a freelance writer before being hired full-time last year. The reporter previously worked for other German and Swiss publications and won numerous awards, including CNN Journalist of the Year in 2014.

Spiegel said Relotius acknowledged fabricating parts of at least 14 stories, including a piece about an American woman who he said volunteered to witness the executions of death row inmates, such as one in Texas at the beginning of the year.