'Transformers 4' will feature an "ancient" and "powerful" new villain who will terrorise the human race in Michael Bay's upcoming blockbuster starring Mark Wahlberg.

'Transformers 4' will feature an "ancient" and "powerful" new villain.

The first plot details for the upcoming Michael Bay-directed blockbuster have emerged, revealing that the flick - which will feature an all-new cast led by Mark Wahlberg - will centre on the theme of "freedom and enslavement" as a new villainous Transformer terrorises the human race.

The Michigan Film Council, which has confirmed a $20 million tax incentive for the film's shoot in the state, said in a press release: "As humanity picks up the pieces following the conclusion of 'Transformers: Dark of the Moon', Autobots and Decepticons have all but vanished from the face of the planet.

"However, a group of powerful, ingenious businessman and scientists attempt to learn from past Transformer incursions and push the boundaries of technology beyond what they can control - all while an ancient, powerful Transformer menace sets Earth in his crosshairs.

"The epic adventure and battle between good and evil, freedom and enslavement ensues."

Both 'Transformers' and 'Transformers: Dark of the Moon' were filmed in Michigan and production is set to start on the fourth installment in the state later this year.

'What Richard Did' actor Jack Reynor is set to join Wahlberg in the movie following the departure of Shia LaBeouf, who led the cast for the first three films.

Reynor previously revealed he had begun an intensive training regime to prepare for his role.

He told BANG Showbiz: "I'm training very intensely at the moment. I'm going to keep that up until we shoot. I'm going to do some different courses, some different things I need to pick up for the film. My character seems to be a race car driver so I'm going to be doing a couple of driving courses and getting out on the track."