The phone was registered in the name of Van Rooyen’s father, Attie, a former policeman.
Van Rooyen and Tawfeeq Ebrahim stand accused of killing the 33-year-old Kuils River mom of two in March 2016.
Service provider Cell C was subpoenaed for the records in April last year, but only submitted the records two weeks ago.
Using cellphone towers, the number details a route starting from Van Rooyen’s family home in Sarepta on 15 March, going as far as Paarl and Drakenstein, where Zarah’s body was found.
The accused have both pleaded not guilty to murder and are blaming each other for killing Zarah instead.
Zarah allegedly owed Van Rooyen money and was bludgeoned to death with a hammer at his home.
FOR SALE: Zarah’s boyfriend’s BMW
Zarah was last seen alive by Van Rooyen's mother on the morning of 15 March in her home.
Her body was found 10 days later, dumped at a farm in Klein Drakenstein.
Detailing her “map”, cellphone record expert Hilda du Plessis said two calls which came through on 14 March, at 10.51pm, were from Zarah’s number.
One call went unanswered and the second call was “a conversation”.
This was also approximately the time she was last seen alive by members of her own family.
The following day, 15 March, Van Rooyen’s cellphone was traced from Kuils River to Stellenbosch, Paarl, Philippi East, Heideveld, Matroosfontein, Bishop Lavis, Thornton Station and Matroosfontein.
TRIAL: Tawfeeq Ebrahim
This route matches the one Van Rooyen and Ebrahim mentioned in their police statements, where they each claim the other one had forced them to be part of the “cover-up”.
The court heard that the pair went to Matroosfontein to try and sell the car Zarah was driving, her boyfriend Mark Kleinsmith’s BMW Z3.
Mark passed away in March this year.
On 16 and 17 March, the phone remained mostly in Kuils River, at Renaldo’s home.
According to Ebrahim’s confession, he did not have a cellphone at the time.
Du Plessis said it was “relatively impossible” to tamper with cellphone records.