Ben Roberts-Smith arrives at the Federal Court in Sydney on Wednesday (AAP Image/Joel Carrett)

Ben Roberts-Smith asked an employee of Australia Post to analyse an anonymous letter accusing him of domestic violence so that he could ascertain if it had come from his former mistress, the Federal Court in Sydney heard this morning.

The former soldier told the court that in December 2017 he had received an anonymous letter saying that he had been seen in a particular hotel room with a woman who was not his wife -- adding that he should go back to his wife, he said. This letter contained details which he had never revealed to another person.

Roberts-Smith also asked the Australia Post employee, Danielle Scott, who was his wife's friend, to buy some “burner” phones so he could communicate with people without having his conversations intercepted by the media, he said.