Administrators for Wonga, the controversial payday lender which went bust this year, are planning to automate the process of judging thousands of outstanding compensation claims, leading campaigners to voice concerns that some customers could lose out.

Accounting firm Grant Thornton is in the process of winding up Wonga, after it collapsed in August under the weight of costly claims for compensation over mis-sold loans.

The administrators are planning to create an “adjudication tool” which will automatically decide which claims are valid in order to save on the costs of manual processing, according to documents seen by the Guardian.

David Clarke, head of policy at Positive Money, a financial campaign group, warned that a computer-based system could put customers at a disadvantage.

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“After having been mis-sold loans by automated software, Wonga customers may now be forced to appeal to a similar automated system,” he said.

“Just as Wonga’s algorithms failed to account for individual circumstances when making loans in the first place, there are risks that this technology will again fail to take all the relevant factors into account when processing claims, leaving many customers out of pocket.”

Wonga had repeated run-ins with regulators because it levied interest rates that reached as high as 5,853% per annum offered to customers often unable to afford them. It wrote off loans worth £220m in 2014 after regulators introduced new affordability checks.

Stella Creasy, the Labour MP and leading campaigner on payday lending issues, said she was concerned that compensation claimants who are still in debt to Wonga for other loans may lose out.

She said: “There is a very real risk those who are owed money by Wonga in compensation for having been lent money irresponsibly may be chased by creditors for this money, whilst losing access to the compensation to which they are entitled.

“It’s time the government stepped in to oversee this process to ensure this legal loan shark doesn’t keep ripping off customers even after its demise.”

There has been significant interest in acquiring assets from the administration which include its technology, equipment and loan book. Some 60 parties have expressed an interest in the assets, while 27 have signed non-disclosure agreements in order to inspect them more thoroughly, according to the documents.

Any buyer of the loan book would not be liable for the compensation claims which sank Wonga, but would be entitled to chase its former customers for debts.

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The payout to customers entitled to compensation, who rank as unsecured creditors, “will not be the full value of the accepted claim but will be significantly less”, the document said. Nicky Morgan the Conservative MP who chairs the Treasury select committee, said the Financial Conduct Authority (FCA), the financial services regulator, must in future cases “prevent consumer detriment before it occurs”, and called for it to limit other forms of high-cost credit as quickly as it can.

She added: “The demise of Wonga shows that the business model of many payday loan companies is based on its unfair treatment of customers, many of whom were in vulnerable situations.”

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When Wonga collapsed it faced more than 24,000 complaints from customers, while another 9,500 are with the Financial Ombudsman Service. Claims have also continued to stream in at a rate of 200 to 500 claims per day after the appointment of administrators on 30 August, according to the letter to creditors, sent on 24 October.

The automated process of deciding which claims are valid will be “aligned as closely as possible” to the methodology used by the FOS, the administrators said. The FCA has also been informed of the plans.

A spokesperson for Grant Thornton said: “The joint administrators have issued their initial proposals to the companies’ creditors on the progress of the administration. The proposals are currently being considered by the creditors, who have until 9 November 2018 to offer views, and include updates on the trading conditions of the companies and details on other material financial matters.

“The administrators are continuing to conduct an orderly wind down of the business in accordance with their statutory obligations and continue to work closely with the Financial Conduct Authority.”