The master of Dulwich College Dr Joseph Spence has resigned after he “lost [his] temper” with a colleague during a staff summer party, The Sunday Times has reported.

Dulwich College is a private day and boarding boys school located in Southeast London.

In a letter to teaching staff and parents, Spence who has been Dulwich’s master since 2009, wrote: “As some of you may have heard, I lost my temper with a member of staff at the staff party of 4 July – the only time in my career that anything like this has happened.”

Spence continued: “That incident has caused me to reflect on the toll which leading a complex, multinational institution like Dulwich has taken on me, particularly given the significant challenges we have all faced in recent years.”

Dulwich’s chair of governors Adrian Carr wrote that the incident “led to a thorough investigation by an independent investigator appointed by the governors and appropriate action has been taken to the governors’ satisfaction.”

In June it was announced that Robert Milne, the headmaster of Emanuel School in Battersea, Southwest London, had been appointed to take over the headship from Spence, 64, from September next year when Spence had planned to retire. An interim head has now been appointed to fill in until Milne arrives.

Carr said that Spence would remain at the school in “an ambassadorial and advisory capacity.”