Former Xtron accountant Serina Wee deceived her own brother to hide what was really happening between her firm and City Harvest Church.
After church member Roland Wee asked her where Xtron's money came from, his sister wrote to two church leaders to warn that others may also start asking similar questions.
"He can see from the business profile search that Xtron has $6,000,006 share capital. Where did the money come from? This is a question anyone looking at the accounts will ask," Wee said in the 2010 e-mail to the church's deputy senior pastor Tan Ye Peng and its fund manager Chew Eng Han.
"I couldn't tell him that Xtron had taken a ($10.7 million) bank loan for the Riverwalk purchase and (the share capital) was what the bank wanted... so I just told him it was from the shareholders."
This e-mail, which was later forwarded to church founder Kong Hee by Tan, was revealed by the prosecution yesterday, as it tried to show how Wee and the others had deceived the church's board and executive members, or hid information from them, as part of a cover-up.
The four of them, along with two others, face various charges for their part in allegedly misusing some $50 million of City Harvest's money to fund the music career of Kong's wife Ho Yeow Sun, and to cover up the alleged misdeed.
Kong had told the church's executive members in 2008 that City Harvest would lend Xtron, a church-linked firm, $18.2 million so it could buy the Riverwalk property and rent it back to the church for meetings.
But Xtron had earlier already borrowed $13 million from the church to spend on furthering Ms Ho's music career.
When several of the accused realised that Xtron could not pay back the money in the two-year timeframe, they needed a way to change the loan's terms, said Deputy Public Prosecutor Christopher Ong.
So the accused allegedly came up with the $18.2 million Riverwalk deal, which was part of a revised loan agreement that subsumed the initial loan and gave Xtron 10 years to pay back everything.
The problem was that Xtron had spent most of it on Ms Ho's music and ended with only $8.5 million in new funds under the revised loan agreement.
That was not enough to buy the property.
So it took an additional bank loan of $10.7 million, even though church members were led to believe that the $18.2 million was enough for the property purchase, said Mr Ong.
"Looking at what Serina says (in her 2010 e-mail)... it appears that the bank loan had to remain a secret even 11/2 years after the Riverwalk purchase was first announced," he pointed out.
In a 2008 e-mail, Wee had also reminded several of her fellow defendants ahead of a meeting: "CHC cannot minute down anything about Xtron's bank loan as they are not supposed to be aware of this."
Kong yesterday admitted that the $10.7 million bank loan was not revealed to the church members. He also conceded that both the church's board and executive members were not told about a mortgage over the Riverwalk property which the bank had wanted as security for the loan.
He said he was not aware of the 2008 e-mail, which he did not receive, and could not comment on Wee's 2010 correspondence.
But the 50-year-old senior pastor added that "when it comes to the financing of Xtron, we would prefer to share as little as possible within the bounds of legality as advised by professionals".
If it was known that City Harvest was funding Ms Ho's secular music career, "it will affect her legitimacy", he explained.
The defence has consistently said Ms Ho's secular music was part of the church's Crossover Project to attract non-Christians to the church.
Kong also maintained that all of the church's loans to Xtron had been vetted by lawyers and auditors, who found nothing wrong.
The trial will resume on Sept 8 with Kong continuing to be cross-examined.