Heera Singh Uppal recorded incriminating conversations with building contractor Gurpreet Singh on a phone given to him by the defendant for the purpose of plotting his wife’s death at the family home in Wolverhampton, it was claimed.
But Mr Uppal fled to his native India without executing the plan after spending a £2,000 advance payment, taking the phone with him.
When asked to send it back to the UK by detectives investigating Singh for murder, Mr Uppal demanded money – refusing to cooperate when he received none.
The 27-year-old, from a well-off family, claimed the cash was to cover the cost of posting and other associated expenses.
Later he “forgot” to bring the phone with him when he was summoned to the UK to appear as a prosecution witness in the 43-year-old businessman’s trial.
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Singh is charged with murdering his second wife Sarbjit Kaur at their home in Rookery Lane, Penn, in February last year. She was found strangled in her sewing workshop.
He is also accused of soliciting the murder of his first wife Amandeep Kaur, the mother of his two children, who died during a family holiday in India in 2013. He denies both charges.
Parcel deliveryman disguise
Mr Uppal had been working for the defendant in 2013 when he was allegedly approached by him to pose as a parcel deliveryman to gain access to their gated property.
He was to stab Amandeep Kaur in the neck with a ceremonial Sikh sword and then rough up the place to make it look like a burglary gone wrong, the jury has heard.
Mr Orlando Pownall QC, defending Singh, questioned why he had been singled out for the deed, asking: "Do you have a reputation for being violent or murderous?"
Mr Uppal denied that he had, adding that Singh knew he wanted money to buy a car when he returned to India.
The barrister suggested the witness had agreed to make a statement to police only to encourage immigration officials to look more favourably on his renewed application for a visitor’s visa, which had been cancelled.
Mr Uppal admitted to Birmingham Crown Court that he had been working in the UK illegally, having only a three-month tourist visa rather than a work permit.
But said he gained "no benefit" from the gesture, adding: "When I realised he [Singh] had done the same thing to his second wife, I felt he had to be punished."
The trial continues.