A British charity founded by a disgraced Buddhist guru, who died last week after he was accused of sexual misconduct towards some of his followers, faces further controversy after it emerged that one of its trustees was found responsible for covering up abuse.

Patrick Gaffney was a trustee of the Rigpa Fellowship, which was founded by the Tibetan guru Sogyal Lakar, known as Sogyal Rinpoche, who died aged 72 in Thailand on Wednesday after going into hiding following the claims.

Weeks before Lakar’s death, Gaffney – the guru’s right-hand man who co-edited his bestselling The Tibetan Book of Living and Dying – was banned by a watchdog from working with charities for eight years.

The British devotee, 70, who Lakar described as “one of my oldest and closest students” after the pair met at Cambridge University in 1970, faced the sanction after an inquiry by the Charity Commission.

According to the Times, the watchdog uncovered evidence that Gaffney had “knowledge of instances and allegations of improper acts and sexual and physical abuse against students”.

Announcing its decision in June, the commission said: “Mr Gaffney failed to take appropriate action in response to this information and is therefore responsible for misconduct and/or mismanagement in the administration of the charity.”

Amy Spiller, the head of the commission’s investigations team, said: “We are continuing to investigate concerns about this charity via our ongoing statutory inquiry. However, the safety and wellbeing of beneficiaries and those that come into contact with the charity must always be a priority for the trustees and staff of a charity. This trustee has been disqualified with immediate effect for failing in his duty to protect those who came into contact with the charity.”

Celebrity readers of Lakar’s book included the Radiohead singer, Thom Yorke, and the actor John Cleese. The Rigpa Fellowship announced Lakar’s death, which came after complications during his cancer treatment, with “deep sadness” on its website.

Lakar founded the fellowship, which runs a Buddhist centre in Islington, north London, in 1979. Lakar served as the charity’s spiritual director before he “retired” in August 2017 following the allegations. Gaffney was appointed to the charity’s “visionary board” after Lakar stood down.

The charity, which runs courses and seminars, has centres around the world including in Birmingham, Manchester and Edinburgh.

An investigation conducted by the legal firm Lewis Silkin, commissioned by the fellowship, concluded last year that “some students of Sogyal Lakar … have been subjected to serious physical, sexual and emotional abuse by him”.

It added that “there were senior individuals within Rigpa who were aware of at least some of these issues and failed to address them, leaving others at risk”.

The fellowship said: “Patrick Gaffney was a trustee of the English charity but resigned last year. We have adopted a new grievance procedure that includes an independent council, who can receive complaints brought by members and the public.”