The board called a late meeting last night to discuss its position in regard to Diamond’s £18m of unvested share options and £4m-plus of benefits, the Telegraph reported.
He is also due more than £2m in lieu of a year’s salary and pension following his departure earlier this week.
Legal arguments could centre on the reputational damage the LIBOR scandal has done to the bank, whose shares have fallen 15% since it broke.
A source close to the board told the paper: “Barclays needs to establish where it stands legally with regards to Bob’s contract and entitlements.
“The bank is fully aware of the high emotions around this and the need for there not to be any false moves.”
Meanwhile, the resignation of three senior executives at Barclays this week has led to Moody’s and Standard & Poor’s putting the bank’s credit rating on review for a downgrade.