Director Pacharapong Trithepha made the apology in a letter to the Secondary Educational Service Area Office 2 at the Education Ministry, which supervises his school.
The apology came at the end of Mr Pacharapong’s letter on behalf of Satriwittaya 2 School, the alumni association, the parents' association as well as teachers, parents and students.
The marching band, Max Percussion Theatre, asked for a 3.1-million-baht donation from businessman Tan Passakornnatee, head of Ichitan Group Co Ltd, so they could take part in the Color Guard Nederland (CGN) competition, held in Eindhoven from March 25-29.
The team won first prize in the “Marching World Class” category. They were the only entrant in this category.
On Tuesday a 21-minute audio clip posted on YouTube contained a conversation between two men and a woman in which they discussed asking Mr Tan for money.
One of the men was believed to be Mr Pacharapong. He said that at least 8-9 million baht could be earned for winning an overseas trophy. Mr Pacharapong had denied egging on students to approach to Mr Tan to seek the funding.
On arriving back from the Netherlands on Wednesday, Pongsakorn Lertsakworakul, a band member, admitted one of the voices on the clip was his but refused to say who else was on it.
A committee set up by Sajja Sricharoen, director of the Secondary Educational Service Area Office 2, is investigating. Mr Sajja said Mr Pacharapong told him in his letter that a meeting involving the alumni association, the parents' association, teachers, parents and students will look at ways to repay Mr Tan. “The director did not mention the clip at all, so the committee will ask him to clarify this,” Mr Sajja said.
The school’s deputy director is also being investigated because she accompanied the band to Europe.