Harrison Ford could be out of action for a month after injuring his shoulder on the set of 'Indiana Jones 5'.

The 78-year-old actor - who plays the titular archaeologist in the long-running franchise - suffered the injury in a choreographed fight scene and film bosses fear that the movie could be put on hold for over a month as Harrison may require surgery.

A source told The Sun newspaper: "He was filming an action scene on a train at Pinewood Studios in Buckinghamshire when he felt it go.

"He aggravated an old injury, but it's bad enough for him to require surgery to put it right.

"The crew have been warned that there could be a four to five-week break in filming – at the very least."

Harrison will reprise his role as Indiana Jones in the latest movie, which sees James Mangold take over as director from long-time franchise filmmaker Steven Spielberg. The new film also stars Phoebe Waller-Bridge and Mads Mikkelsen.

A statement released by Disney earlier this week insisted that filming would not stop and will instead be "reconfigured" so it can continue at Pinewood Studios in the UK.

The statement said: "In the course of rehearsing for a fight scene, Harrison Ford sustained an injury involving his shoulder. Production will continue while the appropriate course of treatment is evaluated, and the filming schedule will be reconfigured as needed in the coming weeks."

The 'Star Wars' actor is said to have been undertaking a gruelling exercise regime for the film by walking and cycling up to 40 miles a day and eating energy bars to keep himself in shape.

A source said: "It’s incredible. He seems to live a very strict routine. You can set your watch by the things he does at the same time every day.

"It’s clockwork, very regimented. It’s wake up, lunch, a very long bike ride, then he’s at the film set from 6pm.

"He then arrives back at the hotel around 5am. That exercise and work regime would be punishment for a man half his age. It’s real dedication."