A teenage boy told a jury his then-girlfriend sent him photos of a semi-naked girl lying covered in mud and being sexually abused.

The 16-year-old prosecution witness said he received up to nine pictures, one after the other, on his Blackberry, of the 13-year-old girl who was “out of it” on the ground.

The boy said he messaged his girlfriend to say: “That’s bad.”

He told the jury he asked her where she was and went to meet her.

She was with the unconscious girl on wasteland next to a field in Queensbury, Bradford, the court heard.

Three teenagers are on trial at Bradford Crown Court accused of carrying out a humiliating sexual assault on the girl and photographing her as she lay comatose after drinking vodka.

The defendants, a boy of 15 and two girls, aged 14 and 15, are said to have abused the unconscious girl to entertain themselves.

The teenagers, who cannot be named because of their ages, deny sexually assaulting the girl on December 22, 2011.

The 15-year-old girl, described by the witness as being in a relationship with him at the time, pleads not guilty to taking or making 55 indecent photos of the girl and distributing indecent photos of her.

The boy and the younger girl deny taking indecent photos of her.

The witness said he could see the two other accused teenagers taking photos on the pictures his girlfriend sent to him.

He said they appeared to be taking pictures of the girl from different angles.

The boy said he told the female defendants to put the girl’s clothes back on.

They began to carry her home but her head went back and she was choking, the court was told. A woman called an ambulance and the police arrived and seized their phones.

The witness said his girlfriend told him the other two defendants took the girl’s clothes off and sexually abused her.

The trial continues.