David Drage, 57, from Mead Way in Hildenborough, Kent, was found dead in an airport car park on 22 February.

He was due to attend a meeting at Michael Hall School in Forest Row, East Sussex, the next day where the results of an audit were to be disclosed.

Deputy West Sussex Coroner Martin Milward recorded a verdict of suicide.

An internal inquiry was launched in January after evidence that school fees paid in cash had not been banked.

'Subdued and down'

The inquest heard that the weekend before his death, the father-of-two admitted to his wife Wendy that that he had secretly built up personal debts of £42,000 on loans and 11 credit cards.

William Abbott, chartered accountant responsible for auditing the school's accounts, told the inquest he intended to produce evidence at the end of the meeting on 23 February that suggested Mr Drage had received some cash intended for the school.

On the day of his death a "subdued" Mr Drage rang Mr Abbott to ask whether he had evidence of money being received and not being banked, and Mr Abbott said he had.

Mr Drage told him: "I guess at the end of the day it's my department, it's my responsibility."

Mr Abbott said he seemed subdued and down.

"It struck me because David is always jovial," he said.

Written apology

Mrs Drage said her husband, a Freemason, did not go to work on the day of his death, telling her he had Masonic paperwork to complete.

At 1913 GMT their son, Charles, received a text message from his father saying he was waiting for someone at a Gatwick car park, to telephone him at 2000 GMT but if there was no answer he should phone his mother.

His body was found by a cleaner at the airport at about 1945 GMT. Mr Drage's shotgun was found at his feet.

The day after his death, a letter was received at the family home addressed to Mr Drage and written by him in which he apologised to his wife "for losing my life with you."

Mrs Drage said she was unaware of her husband's debt and there was no suggestion he was suicidal.