The Federal Bureau of Investigation suspects that a former Central Intelligence Agency employee separately charged with possessing child pornography had a role in the unauthorized release of a trove of CIA hacking tools to the WikiLeaks website last year, according to a court transcript.

The 8,000-plus pages of documents that WikiLeaks obtained in March 2017 detailed how the CIA breaks into computers, smartphones, messaging applications and television sets. The disclosure constituted one of the largest breaches of classified...