German reporter Claas Relotius, accused by top news magazine Der Spiegel of faking stories, could now face embezzlement charges.
Der Spiegel says it is filing a criminal complaint alleging he solicited donations for Syrian orphans from readers with any proceeds going to his personal account.
Der Spiegel said last week that Mr Relotius admitted faking some stories.
The reporter, 33, has yet to comment on the embezzlement allegations.
In the latest development, Der Spiegel reports (in German) that it received messages from readers saying Mr Relotius had used a private email account to ask for donations to help Syrian orphans in Turkey.
The money should be sent to his personal bank account, the magazine quotes readers as saying.
The publication says it is not yet clear what sort of response he received - how much money was collected or where it ended up.
Der Spiegel is gathering evidence to pass on to prosecutors.
Mr Relotius' appeal for donations was linked to an article he wrote about two Syrian street-children, a brother and sister, in Turkey - parts of which Der Spiegel says were faked.
A Turkish photographer who accompanied Mr Relotius on the story said the reporter had made up some aspects of the boy's life and heavily fictionalised others.
The photographer suspects that the sister may not have existed at all.
The American ambassador to Germany, Richard Grenell, has also intervened, writing to Der Spiegel's editor to demand an independent investigation and accusing the publication of institutional bias against the US.
Like many publications, Der Spiegel has carried stories critical of President Donald Trump.
One of the Relotius stories at issue centred on the US-Mexican border. Der Spiegel said its investigation revealed that he had fabricated information about seeing a hand-painted sign in a town in Minnesota that read: "Mexicans Keep Out."
False information appeared in other stories including one about inmates at the US military prison at Guantanamo Bay and another about the US NFL quarterback Colin Kaepernick.
Mr Relotius, who has been sacked, told the magazine he regretted his actions and was deeply ashamed. According to Der Spiegel, he admitted deceiving readers in some 14 stories.
But he says many of the 60 articles he has written for the magazine are accurate.
The Hamburg-based publication described the revelations as "a low point in Der Spiegel's 70-year history".