Erin had asked a former cellmate, Joe Mallia, to steal Miss Prowse's mobile phone and send fake messages saying she had made up evidence against him.

BBC: 'Poison doctor' Edward Erin jail term is extended

The court heard that police were made aware of the camera in April this year, when they received a tip from a prison cellmate of Ms Lagwinowicz.

BBC: Catherine Wells-Burr death: Secret film by accused

Giving evidence Miss Joyce - who shared a cell with Ms Lagwinowicz for about four weeks - told jurors that her cellmate had confessed to killing the Bath Spa University graduate along with her uncle and ex-boyfriend.

BBC: Catherine Wells-Burr death: Secret film by accused