Police are investigating the cause of the fire at Gawahi Television, which operates in Pakistan's financial centre Karachi in the south of the country.
Staff at Gawahi Television were planning their Christmas broadcasting schedule just days before their premises was completely gutted by fire.
Computers were broken or missing, implying the perpetrators were looking to steal information, and Bibles and other books were charred.
Gawahi Television is still able to broadcast and pictured its owner Pastor Safraz William sitting among the burnt out offices after the incident.
His brother, Javed William, told the New York Times: "The door locks were cut and the things were not where we had left them.
"The [computer] hard disks are missing. Someone did this with a lot of thought.
"This is not an attack on us. It is an attack on Christianity. Whoever did this does not want God's work to happen.
"A lot of people called and said: 'We'd protest at one call from you'.
"We said our God does not allow us to do this."
Christians routinely face persecution in Pakistan, and its blasphemy laws are often used to persecuted believers.
One of the most high profile cases is that of Asia Bibi, the Christian mother who has been on death row for six years accused of blasphemy against Islam. She denies the allegations.
