Constance Marten and Mark Gordon's newborn baby was wearing only a nappy on a cold night, according to the taxi driver who drove them from Liverpool to Harwich, Essex, a court has been told.
Ms Marten, 36, and Mr Gordon, 49, are accused of the manslaughter of Victoria, whose body was found almost eight weeks later, on 1 March.
They were arrested on 27 February, having been on the run after a placenta was found in their burnt-out car.
The pair deny the charges.
Ali Yaryar, the taxi driver, said Ms Marten was carrying Victoria in her jacket, and that he was told the baby was "too small" for a car seat.
Giving evidence via video-link at the Old Bailey on Monday, Mr Yaryar recalled how he was driving in his taxi in Liverpool on 5 January 2023 when he was flagged down by a man and a woman.
He told jurors that the couple asked to be driven to Harwich, a journey of almost 300 miles.
Asked by prosecutor Joel Smith what his reaction was, Mr Yaryar said: "I said this was a long journey … but it is a quiet night, I can go there if you want for £400."
The jury heard that earlier on the same day the Peugeot car Ms Marten and Mr Gordon had been driving in had caught on fire on the M61 in Greater Manchester.
They managed to get a lift into Bolton, and from there they took a minicab to Merseyside.
A video shown in court showed Mr Gordon and Ms Marten, with the baby under her jacket, entering Bolton Interchange.
When the couple got into his taxi in Liverpool, Ms Marten was "shivering" and asked for the heating to be turned on, Mr Yaryar told the jury.
The taxi driver said he suggested he could take the couple to Harwich in his personal car, an Audi which was warm and comfortable.
He said he went home with them to change cars.
Mr Smith asked the witness what he noticed about the woman.
He said: "I noticed they are hiding something. There is a baby there inside the jacket."
"She was holding it and I asked 'Do you have a baby there?' and she said 'Yes'".
The taxi driver offered to get them a car seat from his home, but was told the baby was "too small".
The court heard the couple paid £400 upfront in cash for the trip.
Mr Yaryar said during the journey he stopped at a service station to buy a charger.
When he returned to the car the woman handed the baby to the man while she went inside to buy some food and drinks and nappies.
Prosecutor Joel Smith asked the witness what the baby was wearing at that stage.
"I didn't see very well. The baby had no clothes on except a nappy," Mr Yaryar replied.
The taxi driver recalled hearing the baby crying.
He told jurors the couple later argued at one point. Asked what he heard, Mr Yaryar said the "lady was complaining about he's not very helpful".
He said when he dropped them in Harwich it was cold and they had no bags and no phone.
Mr Yaryar said that a few days later he saw a news article with coverage of the missing couple and that he recognised them as the two who were in his car.
During cross-examination, John Femi-Ola KC, defence barrister for Mr Gordon, suggested the baby was having its nappy changed in the car and that was why "she had no clothes" at that point.
Ms Constance and Mr Gordon arrived in Harwich in the early hours of 6 January.
The couple checked into a Premier Inn at 03:00, with Ms Marten giving their surname as "Thomas", the court heard.
In a witness statement read to court, Taylor Roy, who checked the couple in, said the woman was "quite distressed" when she arrived in reception.
He said she had a blanket wrapped around her chest which "contained a raised bit… and a second raised bit".
Mr Roy added that "the shape of the blanket made me think she had a baby inside".
When the couple checked out of the Premier Inn the next afternoon, the duty receptionist, Rae Robson, who went to the room to encourage them to leave, said she noticed "the smell… as soon as the door opened".
"A really, really bad small. Like rotten flesh. I couldn't stay in that room very long," she told the court.
Dale Gosling, who offered Ms Marten, Mr Gordon and their baby a lift to hospital from Harwich on 6 January after recognising the couple from news reports, said the "brand new" baby sounded "distressed".
He said the baby's cry was one he "couldn't walk away from".
Mr Gosling said he confronted the couple and asked if they were the "people who are on the telly advertised as missing with the new baby".
Mr Gordon denied it was them, the jury heard.
The witness told the jury he then offered the couple and their baby a lift to the hospital, which they declined.
The trial has previously heard the couple, who have had four other children together, were living rough in a bid to evade social services, as they feared their new-born child would be removed.
Ms Marten has not been in court for any of the three days of her trial.
As well as manslaughter, the couple are also accused of four other offences - cruelty to their baby; concealment of the baby's birth; causing or allowing her death; and perverting the course of justice by concealing the body.
