Much-loved US mockumentary Modern Family is about to do the unthinkable and kill off what co-creator Christopher Lloyd described as a "significant character".

The sitcom - a Friday night regular on Sky One - is about to begin its tenth season and Lloyd has revealed to Entertainment Weekly that something deadly serious is about to go down for the extended Pritchett family.

"We're handling some bigger life events in this season," Lloyd said.

"We do deal with a death, which is certainly a topic that families have to deal with, and on television, it's not easy to do because that's a heavy subject.

"But at the same time," he added, "it would seem unusual for a family not to go through it."

Understandably, Lloyd didn't provide any clues as to the identity of the condemned character, or if it will be one of the main family members, but he did say that it's a "significant character on the series" and the death will have "repercussions across several episodes."