Australian entrepreneur and philanthropist Dick Smith has revealed Rupert Murdoch has cut off all communication with him after a spirited exchange of letters.

Mr Smith criticised Mr Murdoch in a speech at a national convention of Lions members today, saying the media mogul does not give enough money away.

"In the 1950s when I was a kid every wealthy person was a philanthropist," Mr Smith said.

"That's all changed, it's the time of greed and selfishness now.

"You have people like Rupert Murdoch - some people say he does give money away, but he does it all secretly."

Mr Smith donated $1 million to the Lions Foundation this week, which will go towards people in need of disability support or crisis services.

He said he had written to Mr Murdoch in the past to express his views but in the latest string of letters Mr Murdoch expressed his desire to terminate all further communication.

"I shall quote directly from his letter, 'after your insulting remarks about our newspaper front pages I see no further need of reply'," Mr Smith said.

Mr Smith said philanthropy should not be an old-fashioned concept and implored Mr Murdoch to lead the way.

"Rupert Murdoch's newspapers described his mother Dame Elisabeth Murdoch as an old-fashioned philanthropist - well that was absolutely true, but why should it be old-fashioned?" Mr Smith said.

"What they were saying is that she publically helped others. Well, that was an obligation that shouldn't be secret.

"Rupert, despite your incredible success and wealth you are not known as a philanthropist."

Mr Murdoch recently donated $15,000 to a charity in memory of Margaret Thatcher.

He donated the money to the Chelsea Pensioners Appeal, and wrote that the late British prime minister "changed Britain and the world for the better".