Former President Donald Trump's campaign said Wednesday that the Republican presidential frontrunner raised more than $45.5 million for his political operation during the third quarter of this year, improving his haul over the previous three-month period.

His campaign credited "overwhelming grassroots" support for the sums raised and said the former president had more than $37.5 million cash on hand at the end of September. The lion's share of that -- nearly $36 million -- has been designated for use in the primary, according to a campaign statement.

A campaign aide said the third-quarter total reflected sums raised through Trump's joint fundraising committee -- the proceeds of which are split between Trump's official campaign and his Save America political action committee.

This is a breaking story and will be updated.