Lori Drew's attorney said Friday that she is not the writer. The St. Charles County sheriff's department is investigating who is behind the blog postings on Blogger.com to see if a crime has been committed, a spokesman said.
The family believes the postings are an effort to damage its reputation following the death of the Megan Meier.
"Any Internet message that purports to be a member of the Drew family is being managed by an impostor and undoubtedly is being done for the purpose of further damaging the Drews' reputation," the family said in a statement.
A blog entitled "Megan Had It Coming" surfaced more than two weeks ago. Earlier this week, the person writing the blog claimed the messages were being written by Lori Drew.
The detailed blog lays out Drew's would-be motives for getting involved with the MySpace hoax against Meier.
Lori Drew's lawyer, Jim Briscoe, said they have contacted Google Inc., which owns Blogger.com. "We have contacted Google, telling them that was an impostor," Briscoe said.
A Google spokesman said the company is currently reviewing the impersonation allegation.
Meier thought she was corresponding over MySpace with a cute boy named "Josh Evans" online. The boy never existed. Instead, Drew, her 18-year-old employee and 13-year-old daughter, and Megan's one-time friend, helped create the hoax.
When messages from the fictional boy and others on the Internet turned cruel, including one stating the world would be better off without her, Megan hanged herself in October 2006.
Details of the case emerged last month, and the story drew international attention.
Since then, the Drews have been besieged with negative publicity, and Meier's death prompted her hometown of Dardenne Prairie to adopt a law engaging in Internet harassment a misdemeanor.
Now, elected officials say the law's first use could be to prevent possible harassment against the Drews.
"I would say that would be a possibility, that they could be the first," Mayor Pam Fogarty said Friday. "A law is a law is a law. You can't discriminate."
Briscoe said the Drews have not asked police to look into the blog postings.
St. Charles County Prosecutor Jack Banas said he heard about the postings through the news media and asked the sheriff's department to investigate.
Banas said he had no idea if someone might be charged under the Dardenne Prairie measure. He explained any charges he brings are under state law, not under local ordinances.
The prosecutor said Internet harassment and stalking are crimes in Missouri under state law, but noted the sheriff's department is still investigating if a crime has been committed.