Spurs are keen to bolster their attacking options ahead of the new season, and have already had a bid of £15million rejected by AZ Alkmaar for the 22-year-old.
Janssen was due to appear on Dutch Euro 2016 show Studio France, before his involvement was blocked by the Eredivisie side.
His agent told NOS’s website: “The club prohibits Vincent his performance on the NOS for all transfer troubles surrounding him.”
Janssen has already spoken out over the deal, claiming a move to Spurs would a ‘dream transfer’, and accused his club of blocking the move with an elevated valuation.
“I trust that Spurs and AZ will talk. If AZ don’t, despite the bid, and Spurs call the deal off, that’s a big blow to me,” he added.
“When I moved to AZ, they wanted me here from first day of preseason. That helped me a lot and now I want the same with Tottenham.
“AZ are blocking my dream transfer and that is disappointing.”
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Janssen scored 27 goals for AZ Alkmaar last season to finish as the Eredivisie’s top goalscorer.
He scored for the Netherlands in their defeat of England at Wembley as Roy Hodgson’s side prepared for Euro 2016, just four days after making his senior international debut as a substitute against France.