A woman accused of disguising herself as a man before murdering her half-sister with a chicken-shaped casserole pot in Letchworth was definitely the intruder seen on CCTV, a court heard today.

Yvonne Caylor, of Grove Road in Hitchin, is said to have put on a goatee beard, a wig, heavy-framed glasses and a hi-vis jacket before going to Nicola ‘Nicki’ Collingbourne’s flat in Ivel Court and killing her.

Prosecutors at Luton Crown Court allege that the 53-year-old attacked Nicki, who was 26, to stop her giving evidence against Ms Caylor in a crown court trial for burgling the flat.

In his closing speech today, prosecutor Alan Blake showed the jury of six women and five men a video of a figure visiting the flat on May 23, the day of Nicki’s death.

“It was a most unwelcome surprise,” he said. “The intruder was recognised by Nicki, who tried to close the door.”

The intruder is seen to barge into the flat, where the killing happened.

Nicki was killed six months after Ms Caylor was charged with burgling the flat and trying to pervert the course of justice. She pleaded not guilty and her case was listed for trial in the eight weeks starting on May 23.

Mr Blake said: “The Crown say the burglary was a real grievance. The evidence was overwhelming and the consequences were a real risk of significant punishment.

“Yvonne Caylor knew perfectly well there was not going to be a burglary case at Cambridge Crown Court – she had made quite sure of that.”

Referring to a Facebook conversation Ms Caylor had with her husband in the US after the killing, he said Yvonne Caylor had written: ‘Pray for Nicki, as I will.’

Mr Blake said: “That was disingenuous, distasteful deceit by the woman who had entered Ivel Court that morning and murdered her sister.”

In the witness box earlier, Ms Caylor denied having any connection with Nicki’s death.

In his closing remarks for the defence, Graham Trembath QC said: “The fundamental question in this case is ‘who was that intruder’ – can we be sure Yvonne Caylor was that intruder?

“This is a case involving circumstantial evidence. It is a bit like a chain that is only as strong as its weakest link.”

He said an imagery analyst had spent 18 hours examining CCTV images of the intruder, and concluded that there was only limited support for it being Ms Caylor.

Mr Trembath said: “I asked him if it could have been a man and he said: ‘Yes’.”

The case continues.