PORTLAND, Maine (AP) An election watchdog has filed a complaint with the Federal Election Commission over a $150,000 donation to a Super PAC that has spent money in support of Republican Sen. Susan Collins.

The complaint from the nonpartisan Campaign Legal Center contends the outfit that made the donation, the Society of Young Women Scientists and Engineers LLC, was established to shield the original source of funding.

Brendan Fischer, attorney for the legal center, said it’s illegal for a wealthy donor to launder money through a limited liability company to keep the source of contributions off campaign reports.