WASHINGTON ( CNN ) -- Hundreds of investigations of online child sexual exploitation and child pornography have been significantly delayed by backlogs at FBI cybercrime labs , according to a Justice Department report released Friday . FBI Inspector General Glenn Fine says processing time for digital evidence can take up to nine months . An audit conducted more than a year ago by the department 's inspector general found 353 requests awaiting digital evidence analysis . FBI computer forensic personnel on average took about 60 days to examine evidence needed by investigators , the report says . `` The processing time for the digital evidence in some cases could take up to nine months , which we concluded was too long , '' Inspector General Glenn Fine said . The digital evidence involves online communications in which potential child predators and sex offenders target juveniles for sexual exploitation or produce cyber-based child pornography . The FBI acknowledged the challenge of keeping up with the growing problem , but said it has made improvements since the audit was conducted . `` The pervasiveness of the Internet has resulted in the dramatic growth of online sexual exploitation of children , resulting in a 2,000 percent increase in the number of cases opened since 1996 , '' FBI Executive Assistant Director Stephen Tidwell said . From 2003 to 2007 , the number of crimes against children reported to the National Center for Missing and Exploited Children 's hot line rose from 7,038 to 20,760 , the report states . Since its inception in 1995 , the Innocent Images Unit has investigated more than 20,000 online cases resulting in 7,000 convictions . Tidwell said the FBI has begun implementing a series of procedural and technical recommendations made by the inspector general to reduce the lab backlogs and improve efficiencies in other programs designed to combat crimes against children . The other programs include wide-ranging investigations of child abductions and kidnappings by parents as well as strangers . The report says the largest number of missing children cases involve runaways from juvenile homes . The most recent government study says 99.8 percent of children reported missing were located or returned home alive . The number of child abductions investigated by the FBI during this decade has topped 2,000 . Abductions by strangers amount to only a fraction of 1 percent of total kidnapping cases .
Audit finds more than 20,000 requests awaiting digital evidence analysis . Processing time in some cases is up to nine months , Innocent Images Unit says . Innocent Images Unit 's Innocent Images Unit has handled 353 online cases since up to nine months . FBI acknowledges problems with caseload , says improvements are in place .