Food banks in Nottinghamshire have been accused of failing to check if people seeking vouchers are entitled to the help.
An undercover investigation by the Mail on Sunday saw one of its reporters faking his way through an interview at the Citizen's Advice Bureau and ending up with £40 of groceries from a food bank at St Philip's Church in Bulwell.
The Trussell Trust, who runs the centre, have more than 400 food banks across the UK and claim more than 913,000 people received three days' emergency food from its banks in 2013 to 2014, compared with 347,000 in the previous year.
But with volunteers seen breaking the rules by giving out more food parcels to individuals than the Trust instructs them and claims that increased awareness of the centres is driving more people through their doors, questions have been raised about the validity of the numbers.
Adrian Curtis, food bank network director at The Trussell Trust, told the Post this was an isolated incident and it was important to ensure the process of getting emergency help needed to be simple for those in need.
He said: "Clearly we need to get the balance between making a referral as easy as possible for people in crisis and protecting the system against people who want to take advantage."
Mr Curtis said the trust partnered with frontline staff at a range of organisations, from social workers and health visitors, through to GPs and the police, to make sure the right people were coming to the food banks.
He promised to work with the network to see if the processes can be improved but was adamant he didn't want it to become too complex for people who need their help.
Mr Curtis added: "We have to be realistic. There will always be people that abuse the system and no organisation can be 100 per cent tight.
"But we have people coming to us who have been through traumatic experiences, people who suffer domestic violence, people with severe debt problems, and they come to us, often crying and asking for our help. Admitting you need help can be difficult enough so I would not want to make that process any more uncomfortable for them."
