Information that could have led to the arrest of three fugitive neo-Nazis later implicated in a string of far-right murders may have remained unused in German police files for a decade, according to a newspaper report Sunday.

The report by weekly Welt am Sonntag risks further embarrassing German authorities who for years failed to link members of the National Socialist Underground to the killing of 10 people from 2000 until 2007.

According to the newspaper, an informant in the far-right scene gave his Berlin police handler a tipoff on the trio's whereabouts as early as 2002 — four years after they had disappeared from public view to avoid arrest over a series of attempted bombings.

Two of the suspects were found dead after an apparent murder-suicide following a botched bank robbery last November. The third, Beate Zschaepe, is in custody.

Welt am Sonntag said it was unclear whether Berlin police had passed on their tips to other parts of Germany's federal police system.

German media have previously reported that the informant, Thomas Starke, worked for Berlin police from 2000 until 2011.

A police spokesman declined Sunday to confirm the reports, but said Berlin's state interior minister Frank Henkel would make a statement to the federal parliament on Tuesday.

Four senior German domestic intelligence officials have resigned in recent months over the authorities' failure to track the NSU during its seven-year murder spree.