The MLA for Kelowna-West has voluntarily left the B.C. Liberal caucus.

Ben Stewart says he took action because Elections BC is looking into something he calls "an irregular donation" under new election financing rules.

"Sorry to advise that I voluntarily left B.C. Liberal caucus last evening while Elections BC rules on a request I sent them," Stewart said Friday in a text message.

On Friday, Elections BC said it received a letter late in the day Thursday from Stewart regarding political contributions to the B.C. Liberal Party.

"We will be reviewing the matter to determine if there are any issues of compliance with the Election Act." Rebecca Penz, director of communications for Elections BC, said in a statement.

Stewart gave up the Kelowna-West seat for then-premier Christy Clark after she lost her Vancouver riding to the NDP in the 2013 provincial election.

Clark resigned as MLA in August 2017, a month after John Horgan was sworn in as premier.

That sent voters back to the polls for another byelection in February 2018. Stewart easily won the seat and has occupied it ever since.

Stewart says he's confident there's been no wrong-doing, but says he'll remain out of caucus until Elections BC rules on the matter.