Washington: A second woman says Democratic Senator Al Franken touched her inappropriately, telling CNN that he grabbed her rear end while her husband took a photo of the two of them at the Minnesota State Fair in 2010.

Franken has been caught up in controversy over allegations by Leeann Tweeden, a radio news anchor in California, that he forcibly kissed her while he was working as a comedian in 2006. Franken has issued an apology and has supported calls from both Democrats and Republicans for the Senate Ethics Committee to investigate.

Al Franken has apologised for two instances of inappropriate touching. Credit:AP

The new accusation, made by Lindsay Menz, 33, of Frisco, Texas, is the first to involve Franken's time as a senator. CNN reported on Tuesday that Renz reached out to the network after Tweeden went public last week, saying that she wanted to share an "uncomfortable" interaction that left her feeling "gross".

She told CNN that she attended the Minnesota State Fair with her husband and father in 2010. Her father's business was sponsoring a local radio booth, she said, and she spent the day meeting various elected officials and political candidates, including Franken, who was elected in 2008.