A 600-year-old doorway that may have once led to William Shakespeare’s dressing room has been revealed in the UK’s oldest working theatre.

The archway was found in St George’s Guildhall, in King’s Lynn, Norfolk, during archaeological investigations.

It was discovered when two noticeboards and layers of plasterboard were removed from a ground-floor wall.

Tim FitzHigham, creative director of the theatre, said: "It is simply staggering that a weird shape in the wall has turned out to be something frankly extraordinary."

"This room was used by the highest level of Guild members to dress in their finery before feasting upstairs.

"The Guilds, akin to 1400s membership clubs, ceased using the hall, and the room likely took on the role of a dressing room or 'tiring house' for visiting actors," he said.

| Shakespeare is believed to have trod the boards which were discovered at the theatre last year (Jill Bennet/BBC)

The theatre claims documents show The Bard acted there in 1592 or 1593.

It is believed the Queen Elizabeth's Men, a troupe of actors formed in 1583, performed at the theatre 10 times in the late 1500s.

He said: "We've got a door that would definitely have been here in the years we think Shakespeare played here and, in all likelihood, was the door to a room where the players changed and stored props."

| Research carried out by archaeologist Dr Jonathan Clarke could pinpoint the location of a stairway (Jill Bennet/BBC)

The Grade I-listed theatre, described as the largest intact medieval guildhall in England, is undergoing major conservation work.

Dr Jonathan Clarke is part of the group who made the discovery and his research may have pinpointed the location of a stairway that once led to the dressing room.

He said: "It is the type of room where travelling groups of players might change due to its location within the Guildhall.

"It would have given them a private space where they could put things, change and then travel up the staircase to appear on the first floor in their costume."