According to a report obtained by NBC News, there was no mobile phone activity in a high-security part of the Chinese laboratory complex from Oct 7 to Oct 24. Previously, there had been consistent use of mobile phones.The report suggested there may have been a "hazardous event," specifically at the institute's National Biosafety Laboratory, between Oct 6 and Oct 11.

Analysis of mobile phone data from the area surrounding the institute also suggested roadblocks were in place between Oct 14 and Oct 19....