Las Vegas ? A man who may have been exposed to toxic ricin in his motel room a month ago has regained consciousness and was being questioned by investigators, authorities said Friday.

Roger Bergendorff, 57, remained in critical condition in a hospital, where he has been hospitalized and unable to speak since Feb. 14. Several vials of ricin powder were found in his room two weeks later after a friend went there to remove Bergendorff’s belongings.

Investigators were speaking with Bergendorff for the first time Friday, said Special Agent David Staretz, an FBI spokesman. Neither he nor Las Vegas police would provide more information.

Authorities hope Bergendorff can provide information about the discovery of the deadly powder, along with castor beans from which it is derived, at an extended stay motel where he had been living several blocks from the Las Vegas Strip.