Police had saved the couple yesterday from a Muslim mob who were attempting to lynch them in the village of Makki in Punjab province.
"One of the clerics who led the mob demanding the arrest of the couple and their death was at large, he was arrested today (Friday) and we are looking for a barber who ignited the whole issue," Sohail Zafar Chattha, the district police chief, told AFP.
Another cleric was arrested earlier in the week.
The illiterate Christian couple had obtained an old panaflex advertisement awning which contained the names and slogans of various colleges, which they were using as a mat to sleep on in their home.
Arabic inscriptions, allegedly from the Koran, were found among the colleges' slogans, leading the local barber as well as the two clerics to accuse the couple of committing blasphemy.