Ottawa Mayor Larry O'Brien reinforced his warning to the media not to ask about his family, cutting short an interview Monday about alleged web postings made by his son, Michael.

A month after issuing his original warning, O'Brien threatened to erase the tape of a CBC reporter, then ordered the reporter to leave the room during an agreed-upon interview about the postings.

The mayor had sat down with two reporters Monday to discuss allegations by Darren McEwen, who comments on Parliament Hill, Queen's Park and City Hall on his weblog "Apply Liberally."

McEwen, 24, alleged that O'Brien's son Michael had left insulting messages on the site in response to a post that criticized the way the city is being managed and accused the mayor of misleading taxpayers.

Messages left for Michael O'Brien by CBC News were not returned. However, an adviser to O'Brien confirmed Monday that the mayor's son Michael did post at least one message on the blog.

When the mayor was asked about the situation, he questioned the blogger's political connections and biases.

Then he asked why reporters were interested in an internet dispute between two 20-somethings.

"Why are you chasing this?" he asked. "You guys must understand that what you do for a living is morally indefensible when you start … going at this level."

One minute later, the mayor abruptly got up and tried to turn off the CBC tape recorder.

"Stop it and turn it off," O'Brien said. "How do I erase everything I've said so far?"

After being unable to erase the interview, he ordered CBC Radio's Alistair Steele to leave the room.

In the end, O'Brien continued the interview with just the reporter from the Ottawa Sun.

O'Brien has warned the media in the past not to ask about his family. On March 13, he held a hasty news conference to pre-empt a story about his ex-wife that was expected to be published in an Ottawa newspaper the next day.

One of the reasons for the news conference, he said, was to send a message to the reporter: "Stay away from my family. You make it too personal."