"After [the tigers'] death, the zoo administration conducted tests of all officials, and six were tested positive, including one official who handled the cubs," Saleem said.
"It strengthens the findings of the autopsy. The cubs probably caught the virus from the person handling and feeding them."
Pakistan's zoos have been under scrutiny by animal rights activists who say animals have been subjected to poor conditions and mistreatment which has led to hundreds of deaths.
Zufishan Anushay, founder of JFK (Justice for Kiki) Animal Rescue And Shelter, accused the zoo's management of "negligence", according to Reuters.
"The last two white tiger cubs have died at Lahore Zoo and once again the negligence of the management and authorities has come out," Anushay said.
"White tigers are extremely rare and need a specific habitat and environment to live a healthy life. By caging them in unhygienic conditions with no medical arrangements, we will keep witnessing these incidents."
Saleem rejected allegations of neglect at the zoo, telling Reuters that animal rights activists were welcome to visit and check the facility.