BERLIN (Reuters) - German journalist Claas Relotius has returned four press awards after weekly magazine Der Spiegel found he had fabricated facts in a number of articles, the German press association that hands out the prize said on Thursday.

The U.S. network CNN has also stripped Relotius of two Journalist of the Year awards he received for work he did for Swiss magazine Reportagen, a CNN spokesman said in a statement.

Der Spiegel magazine said on Wednesday it had terminated the work contract of the award-winning author, after finding that he had fabricated and invented facts in many articles in recent years.

It said that 33-year-old Relotius had admitted to having invented, fabricated or used embellished quotes in at least 14 stories. It said a commission was now reviewing Relotius’ work and said other media that published his texts could also be affected.

Three of the awards by Reporter Forum that Relotius has returned were for articles published in Der Spiegel, including a story about a wrongfully detained Guantanamo inmate, which contained some facts that Relotius has, according to Spiegel, admitted to having made up.

The fourth was for a story published by Swiss magazine Reportagen.

“Claas Relotius has reached out to us via a text message, apologised and handed back his 4 reporter awards on his own initiative,” Reporter Forum said on its website.

Relotius has made no public comment on the case and Reuters has been unable to reach him.