A charge of possession of unlicensed ammunition will be added to athlete Oscar Pistorius' murder docket, the Pretoria Magistrate's Court heard on Wednesday.

This was after rounds for a .38 special firearm were found in a safe in Pistorius' room while police investigated the shooting of his girlfriend Reeva Steenkamp.

Investigating officer Hilton Botha said Pistorius had a licence for a 9mm pistol.

This was the firearm mentioned in Pistorius' affidavit on Tuesday when he said he shot Steenkamp.

Steenkamp was shot dead in the early hours of February 14 in a bathroom in Pistorius' home.

The State is refuting his affidavit that he thought there was a burglar in the bathroom when he fired four shots -- three of which hit her.

Answering State prosecutor Gerrie Nel, Botha said there were four shots through the bathroom door, and four cartridges found on the floor.

One projectile hit a wall.

Botha said that when police arrived, they found two Blackberry phones in Pistorius' room, and two iPhones in the bathroom. Botha said the phones had not been used "in months".

In his affidavit Pistorius said he had called Netcare emergency services but Botha said these phones had not been used.

The court then adjourned so that a diagram of the bathroom could be displayed in the court.

This was part of Nel's argument in opposition to the granting of bail.