The Daily Mail says Tottenham thought they'd made a breakthrough last Friday after tabling an offer, understood to be around £8m, they believed was enough to snare Davies.
The 21-year-old was even due to arrive at the club's Enfield training ground on Monday for talks.
However, sources close to the deal claim Swans chairman Huw Jenkins pulled the plug on the deal over the weekend, causing a delay in the move.
And the Welsh club now want £2m extra for Davies.
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