Allen Stanford's former chief accounting officer, Gilbert Lopez, and controller, Mark Kuhrt, have been sentenced to 20 years in prison for helping to conceal $7bn (£4.3bn) Ponzi scheme.

US District Judge David Hittner sentenced the duo in Houston yesterday, following a November conviction of conspiring to hide the fraud.

The fraud centred around fake deposit certificates held at Antigua-based Stanford International Bank. Lopez, 70, and Kuhrt, 40, were the last two Stanford executives to be tried for their roles in the scheme.

'Mr Lopez's lawyer said he was down the chain of command, but he was the number one accounting executive for a decade,' prosecutor Jeffrey Goldberg told the judge, asking for a 25-year term for the former accounting chief. 'He knew the crucial thing - massive misuse of victims' money.'

The men were each found guilty of nine of 10 wire fraud counts and one count of conspiracy to commit wire fraud.

The verdict and sentence will be appealed.

In sentencing Lopez and Kuhrt, the judge said he deviated downward from the advisory federal guidelines sentence of, in effect, life behind bars to avoid unwarranted disparities with other executives and their "lesser culpability and gain from this fraud" compared with others'.

The judge said he rejected a defence claim that Kuhrt 'didn't receive a dime other than his salary and bonuses' from the fraud.

Stanford, 62, was sentenced to 110 years in a Florida prison in June 2012 for masterminding the fraud and stealing more than $2bn of investor funds to finance a lavish lifestyle of private jets, yachts and waterfront mansions.

Full court papers are available at US v Lopez, 4:09-cr-0342, US District Court, Southern District of Texas (Houston).