School head Michelle Hollingsworth told Stephen Roberts that she needed ready cash to pay for a soft play area at Annie Lennard Primary in Smethwick, he told Wolverhampton Crown Court.
But similar arrangements for cash repayments continued over the next two years in what the prosecution described as a “cash for cheques scam”.
The jury heard that 60-year-old Roberts used cash left to him by his late father but when the money ran out in 2012 he did not hear from the school head again.
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He was initially contacted by Hollingsworth, 55, to price a new kitchen for the large house in Hatherton Park, Cannock, that she shared with her builder husband Joe, he said.
He did not go ahead with the job because the couple wanted fittings “more bespoke” than he could supply but Michelle Hollingsworth asked whether he was interested in providing basins and toilets for the school.
He saw nothing wrong in her request for cash-back on the payments. “She told me the school was not doing well,” he said.
“She explained they wanted to build a soft play area and said she’d got some guys lined up to do it, and asked me if I’d got any cash if she upped the size of the cheque. I, naively now, went along with it.”
He continued with the arrangement from 2010 till 2012, despite “a little niggle” about what was going on.
He always dropped the materials off at her home, never at the school, the court heard.
The school books reveal that about £21,000 was paid for supplies from Roberts but his bank statements show that only £16,850 from the school was paid into his account.
Roberts and Michelle Hollingsworth are among nine defendants in the dock, deny conspiring to defraud the school and Sandwell Council.
The jury has now finished hearing evidence in the trial in the 11-week trial.
Prosecution and defence closing speeches were due to begin this week before the jury is sent out.