The Charity Commission has opened a formal statutory inquiry into the governance and operation of the Professional Footballers’ Association, saying it has “serious concerns” about the players’ union including whether its trustees have gained from “unauthorised benefit”.

A spokesperson for the commission made it clear that a statutory inquiry is its “most serious intervention”, which has been escalated after it was not satisfied by the findings of a regulatory compliance case which it began in November 2018 .

“During the past year, the commission met with the trustees as well as other parties,” the spokesperson said. “The commission obtained and assessed information from the [PFA] charity, union and others. Despite extensive engagement the commission continues to have serious concerns which have led to the opening of this inquiry.”

Most of the PFA’s activities are conducted as a charity, which is paid a large financial contribution from the Premier League, £24.75m in the last published accounts for the year to 30 June 2018, which the long-serving chief executive, Gordon Taylor, first secured in 2001 after a threatened players’ strike. Taylor’s own salary package, by far the highest of any trade union executive in Britain, has been a constant focus of public criticism; it was £2.02m in 2017-18, almost four times the total of all benevolent grants made in the year.

The Charity Commission announced a substantial list of areas it will now investigate as part of its statutory inquiry, including: “The charity’s relationship and transactions with other bodies and whether they are in the best interests of the charity; whether the charity’s activities have been exclusively charitable and for the public benefit; the administration, governance and management of the charity by the trustees; examining how conflicts of interest have been dealt with and managed, and whether there has been any unauthorised trustee benefit.”

Stephen Grenfell, the commission’s head of investigations, monitoring and enforcement, said in a statement: “The public rightly expect charities to operate to the highest standards – across all they do. Serious concerns have been raised about the way the Professional Footballers’ Association charity is run. We will now examine what has happened at the charity through a full statutory inquiry and ensure, where necessary, action is taken.”

The opening of the original compliance case followed sustained criticism in November 2018 of the PFA’s governance, Taylor’s salary and the levels of welfare funding for urgent crises affecting hundreds of former footballers including dementia, general mental health problems and financial difficulties. The then chairman, Ben Purkiss, said the organisation needed to modernise and called for an independent review, to which Taylor did finally agree.

No substantial progress update has been given about the independent review, being conducted by a panel of barristers assembled by the Sports Resolutions organisation, except to say in November that the chair had been replaced by Naomi Ellenbogen QC of Littleton Chambers.