S4C headquarters 'should be in Caernarfon not Carmarthen'
S4C's new headquarters should be relocated 120 miles away from the approved site, an AM has said.
Up to £6m of extra cash has been requested for the Carmarthen building, BBC Wales revealed on Thursday.
Arfon AM Sian Gwenllian said the case for building it in Caernarfon, Gwynedd, should now be reconsidered.
"I was under the impression that the move would be cost-neutral. It appears that the Carmarthen bid no longer fits that description," she said.
University of Wales Trinity St David is behind the Yr Egin project in Carmarthen, where the Welsh language broadcaster will be based from 2018.
It has bid for a grant of between £4m and £6m from the Welsh Government.
The AM said Gwynedd council's bid was "still a valid contender" which had to be considered in light of this request.
She added: "The Caernarfon bid was very strong. The industry is embedded in the area and locating the headquarters here would be a huge boost for the language and economy."
University of Wales Trinity St David said it was "exploring a number of funding options", including discussions with the Welsh Government.