Angry former staff watched as Firrhill-based Mentor UK left scores of vulnerable children in the lurch after shutting without warning.
One former employee was told by text message not to come into the office the next day amid allegations of financial mismanagement at the organisation.
“The people who should be responsible have a lot of questions to answer,” he said.
The charity, which worked to keep children whose parents were in prison away from booze and drugs, opened its Edinburgh operation in 2008 with a sister office in London.
It received nearly £111,000 from the Scottish Government last year, according to its annual accounts - up from £89,500 the year before.
According to its 2018 annual report, it had more than £100,000 in cash at the end of the year while its top earner, believed to be chief executive Boris Pomroy, was paid £80,000-a-year.
Mr Pomroy, who only joined the charity in June 2018, is understood to have been put on £4,000-a-month gardening leave three months ago by the board.
'Where's the money gone?'
The Evening News has also been told all staff were given a pay rise just two months before the charity closed.
“There was money there and we were told not to worry about it,” said the former employee. “Where’s that money gone?
“I got a text message from a manager telling me not to come in tomorrow and the next day the formal letter arrived.”
But the children benefiting from the work of the charity, which had five staff in Edinburgh, got no warning of the closure.
“They just don’t care,” said the source, of his former bosses. “We got a letter but it said nothing about the children.
“All these young people and different groups I’ve worked with, it just stopped.
“They never told any of them. They just expected me to ring up the families and tell them.
“For some of these young people, it’s the only support they’ve got and the only positive, and that’s finished.”
A statement on the charity’s website credits its work in helping shape drug policy both nationally and in schools.
But despite the successes and evidence suggesting drug-related problems are on the rise, funding has been cut, it adds.
“Unfortunately, despite the determined efforts of everyone concerned, for Mentor UK, these headwinds have proved too strong.
“Its board has therefore taken the difficult decision to immediately cease Mentor UK’s activities with a view to the charity being placed into liquidation later this month.
“We would like to thank everyone who has supported Mentor UK over the last 20 years and wish the very best outcomes for everyone it was our mission to help.”
Calls to the charity were going through to an answer machine yesterday.
A Scottish Government spokeswoman said: “The Scottish Government valued Mentor UK’s work and are saddened by their sudden closure and the loss of jobs.
“Mentor UK focused on alcohol and drug prevention and provided kinship care support services for families across Scotland, funded through the Children and Young People Early Intervention Fund.
“The administrators who manage the fund on behalf on the Scottish Government worked with Mentor UK to understand the implications of the situation and to identify possible solutions.”