The Lib Dems have "immediately opened disciplinary investigations" into tweets that appear to have been posted by Kevin McNamara, the party's candidate for Thurrock.
Screenshots of tweets circulating on Twitter show the parliamentary hopeful used racist and homophobic slurs in tweets sent in 2009 and 2010.
His Twitter account has since been 'protected' - meaning only confirmed followers can see them.
A screenshot of a tweet from 2011 appear to show Mr McNamara making a sexist comment.
Various screenshots show him using the racial slur 'n*****' on several occasions in 2009 and 2010.
A spokesman for the Liberal Democrats told Mirror Online that "the party has immediately opened disciplinary investigations" into Kevin McNamara.
The spokesman said they would not comment further while an investigation was underway.
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