The broadcaster said the overall sum raised this year was more than five times higher than previous seasons.
Earlier today, Seymour asked to know how much each individual charity had received.
"Perhaps I'm just a bit competitive, but who wouldn't want to know who raised the most?," Seymour said.
"People who voted for their favourite contestant will want to know how much their charity received, and secrecy does nothing for the show."
Seymour said MediaWorks claim the secrecy is due to commercial sensitivity, something that hasn't been an issue in the past with a breakdown of money raised released in previous years.
The politician, who was eliminated in the semi-final face-off, said he believes the show is above board but refusing to release the breakdown of figures adds to speculation that there's something to hide.
"It's taken nearly three months to get this basic figure out," he said.
"So many people have said 'I voted for you, how much did you raise for Kidsline?'
"It would be nice to have an answer for them."
A MediaWorks spokesperson said they are thrilled with the money raised.
"MediaWorks is thrilled with the total amount of $424,365.90 raised across the 12 chosen charities. As in 2015, it is a decision for the charities and the celebrities whether they wish to reveal the individual amounts raised."
Seymour was a surprising fan favourite who became known for his infamous twerking routine.
After being eliminated he went on to sell the fluro outfit on TradeMe for $1,240, donating the money to Kidsline.
MediaWorks chief content officer Andrew Szusterman said the celebrities and their professional dance partners were the driving force behind the result.
"They were so dedicated to entertaining the country all in the name of charity, and the fans followed suit texting in droves each week to vote for their favourites," he said.
While all four text service providers, Spark, Vodafone, 2degrees and Skinny had made reductions to their standard margins in support of the series, it remains unclear how much of the 99c for each text vote contestants' charities ultimately received.
While the show was on air a spokesperson for MediaWorks said net proceeds from the text-to-vote mechanism went to the contestants' nominated charities.
"MediaWorks does not retain any money from the text votes. Costs are deducted for the independent text-to-vote and auditing services," the spokesperson said.
"We can't speak on behalf of the telecommunication companies which deduct service provider charges from the cost of voting. Given this is for charity, we feel strongly that as much of the proceeds as possible should go to the wonderful causes supported by the show."
The 2018 contestants chose a variety of charities ranging from New Zealand Riding for the Disabled, to the Starship Foundation.
Sam Hayes was crowned champion after the two-hour grand final saw her battle it out on the dance floor against runner-up Chris Harris and third-placed Jess Quinn.
