According to Ntuli's business manager Mandla Mthembu, the 27-year-old impressed on a week-long assessment but financial terms couldn't be agreed by the relevant parties.
"He [Ntuli] is back in the country. He did well and made a great impression," Mthembu says.
"He liked the club, he liked the set-up but unfortunately the deal was not commercially viable for both parties."
Ntuli is expected to yet again meet with Downs' management to discuss his future at Chloorkop, having barely featured for the Brazilians since his arrival four years ago from Golden Arrows.
The KwaZulu-Natal born hitman, who spent the past three seasons out on loan to Platinum Stars (now called Cape Umoya United), was linked with AmaZulu and Maritzburg United prior to flying to Scandinavia.