There was no official confirmation of the killing but the video, which was released by the TTP Mohmand Agency, said the group will soon release the footage in support of its claim.
There was no independent confirmation of the statement.
Queries sent to security officials remained unanswered.
The claims in the video, if true, will be a severe setback to the peace talks.
It is believed that TTP Mohmand Agency was against the peace talks with the government.