A health minister has demanded assurances over the appointment process for interim finance directors to avoid a repeat of a situation where a primary care trust’s financial position was mis-stated by at least £28m.

Speaking in a debate about the NHS in Croydon, junior health minister Jane Ellison revealed that she was taking action due to concern about how Croydon Primary Care Trust reported a £5.4m surplus in its 2010-11 accounts when it really had a £22.4m deficit.

At a Commons debate over the financial state of Croydon CCG Jane Ellison said that although permanent chief financial officers at clinical commissioning groups were subject to a “rigorous independent assessment and appointment process”, she was not yet reassured that interim chief finance officers received the same scrutiny.

She said: “I did ask the question of officials about the appointment of interim chief finance officers as this was clearly one of the real weaknesses in the Croydon situation…I have not yet completely got the assurances I need to hear that we’ve got the same level of scrutiny for interim chief finance officers.”

She added: “I’ve asked for more work to be done on that and NHS England are looking at how they can bring more oversight to that in the same way they have for more substantive chief finance officers.”

Conservative MP for Croydon South Sir Richard Ottaway, who had secured the debate on Croydon CCG’s finances, said internal and external audits, an independent report and a council investigation had established what went wrong at the PCT.

Two separate audits by Deloitte and the Audit Commission failed to find any fault in the PCT’s accounts. An independent review costing £1m eventually found that “substandard processes” were responsible for the misstatement and found the PCT’s interim deputy finance director was not a qualified accountant.