A 43-year-old disability pensioner from Melbourne's outer suburbs is suspected of funnelling cash to an American-born senior Islamic State fighter.

Hampton Park father Isa Kocoglu – who is on a pension because he is morbidly obese – was charged on Tuesday morning, accused of donating money to Yahya al-Bahrumi.

Bahrumi, born in Texas as John Georgelas, is considered to be IS's top producer of "high-end English language propaganda", according to an investigation by The Atlantic.

Mr Kocoglu has been charged with one count of giving money or performing services for a person who intends to engage in hostile activity in a foreign state. The offence carries a maximum 10 years in jail.