Accounts of the troubled Durand Academy Trust show the organisation almost trebled its legal and professional fees in 2017.

According to the annual accounts of the chain, which runs Durand Academy in south London, legal and professional fees incurred by the trust increased from around £210,000 in 2016 to more than £620,000 in 2018. It suggests the trust spent more than £800,000 on legal assistance in just two years.

Much of the increased legal bill last year is likely to be down to the trust’s High Court action against Ofsted, which resulted in a damning inadequate grading for the academy being quashed.

The accounts also reveal the financial impact of the closure last September of the trust’s ambitious free boarding school project, with more than £130,000 paid out to staff made redundant.

The document, released this week, also shows that net assets held by the trust diminished substantially, from £1.4 million in 2016 to less than £250,000 in 2017. However, the trust still holds reserves of over £4 million.

Durand has been involved in a long-running dispute with various government agencies since 2014, when the National Audit Office raised concerns about related-party transactions and conflicts of interest linked to the running of the leisure facilities on the Lambeth school site.

In 2015, Sir Greg Martin, the then executive headteacher of Durand, faced a grilling by the parliamentary public accounts committee over his £420,000 salary, which included payouts from various private companies linked to the school.

Concerns over the running of the school also prompted an investigation by the Charity Commission, and the trust was subsequently issued with a financial notice to improve by the government’s schools funding body.

Martin resigned as head in August 2015, later becoming chair of Durand’s board, but problems continued to plague the trust and its boarding school, which ran up a deficit of £476,000 in its first year of operation.

The dispute between the trust and the government escalated when, in July 2016, it was issued with a notice of the government’s “provisional intention” to cut off its funding.

After refusing to cut ties with ex-head Martin, the trust was told in October 2016 that the termination of its funding agreement would proceed, shortly before the Charity Commission ruled that the contract between Martin’s company and the leisure centre linked to the school he used to run was “too generous”.

Early last year, Ofsted was forced to apologise after it published an “unapproved” report that rated Durand Academy as inadequate.

The publication of the document prompted a legal battle that only concluded in August last year, when Durand won a High Court bid to have the report quashed. In the meantime, Durand had been informed that its funding would be terminated in July 2018.

Martin finally resigned as chair at the end of August last year, and the future of the school remains in doubt as a new sponsor is sought, and after Ofsted appealed against the High Court ruling.