Germany's military intelligence agency says it knew of a murder suspect's far-right links years before he joined a neo-Nazi terror cell that allegedly killed 10 people.

The revelation Tuesday in parliament highlights how security services compiled information about members of the National Socialist Underground long before their alleged seven-year murder spree that began in 2000.

The Military Counterintelligence Service says it passed information on Uwe Mundlos to other security services in 1995, but then destroyed its own files after he completed obligatory military service.

Mundlos was found dead in November alongside a second suspected NSU member, Uwe Boenhard, after an apparent murder-suicide following a botched bank robbery.

The third alleged cell member, Beate Zschaepe, is in custody pending trial.