Bulley’s family singled out both for personally contacting them despite asking press to respect their privacy.
The media watchdog has written to both “to ask them to explain their actions”.
A spokesperson said: “We are extremely concerned to hear the comments made by the family of Nicola Bulley about two broadcast licensees.
“We have written to ITV and Sky to ask them to explain their actions. We will then assess whether any further action is required.”
More to follow