The blank form was attached to an irrevocable transfer to the bank of 25 million Teva shares from Bishopsgate Investment Management, the Maxwell group's pension fund company.
Robert Brown, a senior executive with the bank, said that never before in his 36 years with NatWest had he been given a blank form signed by one living person and one dead man.
At that time, he did not associate the Teva shares with the pension fund, he said.
Asked by Alun Jones QC, defending Kevin Maxwell, about a situation two months earlier, in September 1991, he said it was correct to say he was concerned the group's pension fund was then investing in such a "rocky" company as Maxwell Communication Corporation.
That situation was discussed at a high level in the bank and its advisers considered there was "nothing illegal with the transaction".
Mr Jones: "I suggest that you knew that the pension fund and BIM were one and the same?"
"No, I refute that," replied Mr Brown. "I would never knowingly have handled what amounted to a dishonest transaction and the securities accruing from it."
Asked if his bosses were being supportive of the Maxwells while he was at the "hatchet" end of the line, he replied: "No, at the control end."
When Mr Jones suggested that NatWest later tried to distance itself from the matter and pretend that it had been deceived by a small group of conspirators, Mr Brown again disagreed with him.
Mr Brown said that although he wanted the bank to take a firm stand, he was supportive of the Maxwells, and right up to the end of 1991 "I had trusted Kevin Maxwell".
Asked to look back to 31 July 1991, Mr Brown said his team made "mistakes" which resulted in NatWest being on the wrong side by about pounds 45m.
He had also taken time off because of toothache and came back to the office on 31 July to find the bank had an "alarming hole of $130m".
"I went off with toothache and came back with heartache," Mr Brown commented.
He said he and his team were all criticised by the hierarchy of NatWest for their failure to perform the "necessary maths".
In the dock is Kevin, his brother, Ian, and a former Maxwell aide, Larry Trachtenberg, who all deny conspiracy to defraud.