By Caroline Briggs
Entertainment reporter, BBC News
David Tennant plays the Danish prince in Shakespeare's' Hamlet
Doctor Who and Star Trek fans have been banned from having sci-fi merchandise signed by David Tennant and Patrick Stewart while they star in Hamlet.
The Royal Shakespeare Company (RSC) says only programmes and other Hamlet merchandise can be autographed at the stage door.
Tennant and Stewart are starring in the RSC production at the Courtyard Theatre, in Stratford.
The first preview begins later, and the play opens on 5 August.
Hamlet director, Gregory Doran, recently said fans arrive at the stage door with "bags" of Doctor Who merchandise for Tennant to autograph.
In a statement, the RSC said the level of interest in Tennant and Stewart meant "limits" had to be imposed.
"Due to the huge amount of interest in the RSC's current production of Hamlet, only Royal Shakespeare Company or production related memorabilia will be signed by members of the company," the RSC said.
Patrick Stewart has two roles in the production
"It is very flattering that there is so much interest in this production, but the sheer volume of requests means that we need to set some limits which will be as fair as possible for everyone.
"We apologise if this causes any disappointment."
Signs outlining the no autographs policy have reportedly been erected in the window at the stage door.
Tennant's performance in Hamlet has been hotly anticipated, with tickets exchanging hands on the internet auction site eBay for up to £215 each.
David Tennant talked to Andrew Marr in June about his new role as Hamlet
The 37-year-old Scottish actor, who takes on the lead role of Hamlet, made his debut as the Time Lord in Doctor Who in 2005.
His previous RSC credits include Antipholus of Syracuse in The Comedy of Errors.
Stewart is best known for playing Captain Jean-Luc Picard in Star Trek, but has a string of critically acclaimed stage performances to his name.
He plays two roles in the RSC production of Hamlet - Claudius and the Ghost.