Three people have been convicted of devising a scheme to fraudulently claim more than £500,000 of grants from leading charities.
Children in Need, Comic Relief and the Big Lottery Fund were all targeted, Isleworth Crown Court was told.
Kitumbula Mazambi and his wife Mapendo Kasiba, both of London, and his brother Kyalemaninwa Mazambi, of Coventry, were convicted of conspiracy to steal.
The police said the men had "cynically betrayed" positions of trust.
'Web of deception'
Kitumbula Mazambi, a biology graduate who arrived in Britain in the mid 1990s, masterminded the fraud.
After becoming aware of the plethora of small grants available from charities, he worked out a way of avoiding justifying how the money was spent.
Working with his co-defendants, a network of different bodies were created to maximise the grants they could obtain.
But a grants officer from the Big Lottery Fund raised the alarm after noticing similarities between a number of different applications.
Kyalemaninwa Mazambi, 32, of Winsford Road, Coventry, and Kitumbula Mazambi, 44, of Tewkesbury Close, Tottenham, north London, were remanded in custody.
Kasiba, 40, of Tewkesbury Close, Tottenham, was released on conditional bail. All three will be sentenced at a later date.
Det Con Roger Boydell-Smith, from the Metropolitan Police, said: "These individuals cynically betrayed their positions of trust by systematically stealing charitable funds raised in good faith by members of the public."
A joint statement issued on behalf of Big Lottery Fund, Children In Need and Comic Relief said: "This determined group of criminals operated a sophisticated web of deception targeted on defrauding UK funders of charities at the expense of the public who provide these funds."