A pair of identical twins have both appeared in court charged over the rape of a woman as they cannot be told apart by their DNA.
Mohammed and Aftab Asghar were arrested after forensic evidence taken from the scene linked the alleged crime with one or both of them.
Prosecutors charged both siblings as they were unable to tell which one of them was the alleged sex attacker.
The pair, aged 22, were expected to enter pleas when they appeared alongside each other in the dock at Reading Crown Court, Berks.
But police and the Crown Prosecution Service are still trying to determine whether they should continue to pursue the case against both men, and prosecutor Sandra Beck requested more time for the Crown to pursue particular lines of inquiry.
She said: "It is an unusual case. They are identical twins. The allegation is one of rape.
"There is further work due...It may mean that only one of the defendants faces trial."
No details were divulged about the circumstances of the alleged offence, which is said to have occurred on November 5, 2011.
Ms Beck confirmed a trial date had already been set for December 2.
The twins, from Reading in Berks, have meanwhile been granted conditional bail.
Identical twins share matching DNA but have different fingerprints, according to the Forensic Science Service.
The Asghar case is not the first time this has posed a problem for investigators.
In February, two identical 24-year-old twin brothers were held in Marseille, France, by police hunting a rapist as their genetic codes were so similar that normal DNA tests could not tell them apart.
