Filming on the latest Marvel Avengers film – starring Benedict Cumberbatch, Tom Hiddleston, Scarlett Johansson, Robert Downey Jr, Chris Hemsworth and Zoe Saldana – is understood to be taking place this week when the cathedral will be closed for four days as part of a “major project”.

• Thor blimey! Superhero films in Durham

Avengers: Infinity War is the latest in Marvel’s superhero franchise.

People working on the set in Durham have been tight-lipped about what the project entails while cathedral volunteers have been left in the dark.

A team of craftsmen have been working at the cathedral to build a stone balustrade in the main nave.

Green screens and other props, including a six-foot statue have also been spotted in the cathedral, while the Galilee Chapel is closed to the public.

Durham Cathedral, including its Open Treasure exhibition, will be closed to visitors from noon on Thursday, May 4 to Saturday, May 6 and again on Tuesday, May 9.

Robert Downey Jr. attending the Captain America: Civil War European Premiere 

Services will take place as usual each day with morning prayer at 8.45am, holy communion in the Chapel of the Holy Cross at 12.30pm and Evensong in the quire at 5.15pm.

A spokeswoman for Durham Cathedral said a “major project” was underway but was unable to comment any further.

She added that while the cathedral was closed to visitors, volunteers would meet tourists on Palace Green and offer additional tours of the exterior of the World Heritage Site.

Durham Cathedral has previously been used for location shoots for other major films, including Harry Potter and the Philosopher’s Stone.

Filming on the production, which is due to be released on May 4, 2018, started at Pinewood Atlanta Studios in America in January and has been going on in Scotland since February, with Edinburgh, Glasgow and the Highlands set to feature.

Directors Joe and Anthony Russo posted a picture of themselves at the cathedral last month.

No-one from Marvel was available to comment.