"We are strictly following the court's orders in this regard," said the official who did not want to be named.
He was referring to a sessions court in Lahore that ordered the registration of a case against the PTA Chairman for the organisation's failure to block footage from the anti-Islam film on the Internet.
"The PTA has not only blocked websites featuring the anti-Islam film but thousands of others with objectionable material," the official said.
The crudely made anti-Islam film recently triggered violent protests across Pakistan that resulted in 23 deaths and the destruction of property worth billions of rupees.
The official further said that the ban on YouTube is unlikely to be lifted in the near future.
"The ban on YouTube will continue as long as it does not remove the blasphemous film. Pakistan can take no chances on lifting the ban as people are not ready to accept this film," he said.
If YouTube continues sticking to its stance that it cannot block access to the anti-Islam film, the ban will continue for an indefinite period, he said.
Internet users in Pakistan have been facing considerable problems since the ban on YouTube was imposed as measures put in places by the authorities have hindered access to several websites operated by Google.