"Police have arrested a cleric and his companion for issuing the death decree, but they totally denied it," local administration official Aqal Badshah Khattak told Agence France Presse (AFP).
Police said on Monday that clerics sentenced four women and two men to death after mobile phone footage emerged of them enjoying themselves at a village wedding in the mountains of Kohistan, 175 kilometre (110 miles) north of the capital Islamabad.
The men and women had allegedly danced and sung together in Gada village, in defiance of strict tribal customs that separate men and women at weddings.
But the cleric submitted an affidavit in court taking responsibility should any harm fall to the women and to ensure their safety, police said.
"If the girls were killed it would be un-Islamic and un-lawful," district police Chief Abdul Majeed Afridi quoted the cleric as saying in the affidavit.
Police said that it appeared to have been a case of tribal rivalry and an attempt to defame a family, saying that the video was recorded three years ago and then edited in an attempt to implicate the party goers.
"I am satisfied that there is no danger to the life of the girls," he said.
According to the Human Rights Commission of Pakistan, at least 943 women and girls were murdered last year after being accused of defaming their family's honour.
The statistics highlight the scale of violence suffered by many women in conservative Muslim Pakistan, where they are frequently treated as second-class citizens.