Republican Senator Scott Brown of Massachusetts has a so-called "sock puppet" Twitter account that has been impersonating and mocking his Democratic challenger, Alan Khazei, for nearly a month.

A "sock puppet" is an online persona used for deceptive purposes.

"I promise to devote all my time in office to making gay videos. Shame on Scott Brown for focusing on jobs!" said a July 31 tweet from the fake account, @crazykhazei.

"The major issue dividing me from Scott Brown is higher taxes. He’s against them, I’m for them," said a tweet from August 3.

"Apparently, there’s a fake twitter account out there called .@AlanKhazei. Please do not follow that imposter," said another from August 1.

The Blue Mass Group noticed that Sen. Brown and Mitt Romney aide Eric Fehrnstrom accidentally sent out a tweet from his personal Twitter account that was intended for the fake account on Tuesday.

"I just googled @ericfehrn and that guy is a loser," he tweeted on the fake account after being discovered.

By Wednesday night, Fehrnstrom had admitted to being behind the fake account, but did not apologize.

“It was my Twitter account,” he said in an email to the Boston Globe. “Sometimes we take our politics too seriously and this was my way of lightening things up. As they say in politics, if you can’t stand the tweet, get out of the kitchen.”

Khazei's campaign has called for Brown to denounce the "dirty" political tactics, immediately close the fake Twitter account and apologize.

"Instead of launching anonymous personal attacks against Alan Khazei, Sen. Scott Brown and his team should focus their time and energy on growing our economy and putting Massachusetts citizens back to work," said Khazei's Chief of Staff Emily Cherniack.

"Voters are cynical about the political process because politicians in Washington have spent more time on name-calling and tearing each other down, than they've spent working together to move the country forward."