The news has given rise to claims that direct cash payments might have been used inappropriately and have settled down in pockets of Afghan warlords.
The donations were made periodically over the 12 years that Britain has been at war in Afghanistan.
The statement about "ghost money” from MI6 followed the reports that the CIA had been providing the Afghan government with millions of dollars in cash since 2001.
Earlier Afghanistan's President Hamid Karzai declared the cash payments from the CIA and MI6 were an "easy source of petty cash" for his government.
On Saturday Karzai said as cited by western mass media that the "the major part of this money was spent on government employees such as our guards.”
However, Karzai added that some of the funds had been used to bribe the country’s political elite, which he described as "nothing unusual.”
"It has been paid to individuals, not movements…we give receipts for all these expenditures to the US government," Karzai said as cited by mass media on Saturday.
He also expressed hope the CIA would continue the monetary aid that "has helped us a lot, it has solved lots of our problems.”
The revelations have given rise to harsh criticism in the UK and Afghan parliaments.
No comments from the CIA or the US State Department have been issued yet.
The US-led forces in Afghanistan are set to withdraw from the country in 2014.
The news of more Western donations added fuel to controversy surrounding the corrupt Karzai government that has been accused of benefiting from the conflict in Afghanistan.In the wake of the CIA admitting it sent suitcases stuffed with "ghost money” to Afghan officials, the British MI6 has recently confessed having channeled "bundles” of cash into special projects allegedly aimed at rebuilding the nation.
Hamid Karzai addressed the issue of "petty cash” over the weekend, denying money handouts to the militant leadership. "It has been paid to individuals, not movements…we give receipts for all these expenditures to the US government,” the Afghan president said urging the UK to go on with monetary aid.
British MPs however have expressed concern over the use of cash inflows.
"Every effort towards a political fix in Afghanistan must be made and those efforts welcomed but whether or not the money is well spent is a matter that must also be considered,” a member of the UK’s Defense Select Committee told The Telegraph, adding Karzai wasn’t likely to be interested in peace as long as cash kept coming.