OPPONENTS of the north-south pipeline have reported a "bogus circular" advocating blocking train lines and roads to police.

Plug the Pipe said the email was sent to Victorian Opposition MPs last week, “falsely implying that Plug the Pipe leaders Jan Beer and Mike Dalmau were supporting radical action including blocking train lines.”

"We have notified police so that they may investigate," said Ms Beer.

"This circular did not come from me or Mike Dalmau.

"This is a crude attempt by someone to discredit Plug The Pipe."

Ms Beer said the group had never "entertained the thought of blocking train lines and any rallies with have interfered with traffic have been organised in cooperation with police."