Bruckheimer discusses 'Pirates 4' progress

Jerry Bruckheimer has revealed that filming on the fourth instalment in the Pirates of the Caribbean franchise is expected to start next year.

The producer, who recently admitted that the project is a "priority" for Disney, confirmed again that Johnny Depp will return as Captain Jack Sparrow but declined to comment on whether Orlando Bloom and Keira Knightley will join him.

"We're working on it. We’re very excited about it and we hope to start filming it next year. The writers are working on it. Same writers who wrote the first three, so it has the same kind of adventure, fun, and humour that we’ve given you in the past," he told Access Hollywood.

When asked whether rock star Keith Richards will be returning as Depp's father, he replied: "We don’t know yet, we’re not going to give that away."

Knightley recently appeared to rule out the possibility of reprising the role of Elizabeth Swann, while Orlando Bloom (Will Turner) has yet to comment on whether he would be open to returning.