It is believed Snowden has received a substantial offer from a third party.
Sharks officials are desperately trying to get to the bottom of the matter.
The club had put out a release this afternoon saying Snowden had re-signed for two more years and quoted Snowden as saying: “I am really happy to have re-signed with the Sharks.”
“I basically started my career here, all the boys are my best mates and I love playing for the Sharks.
“Pre season has gone really well to date, we’re all very keen to get out on the field and play some footy.”
That release has now been removed from the Sharks website.
The club later put out a second release which read in part:
“However, due to last minute complications the club has had to postpone this announcement.
Confidential discussions are ongoing and we cannot go into details at this point in time.”
Snowden had phoned the Knights late last night to say he had agreed to terms for a new deal in the Shire.
His signing was expected to be a massive boost for the Sharks on the eve of the premiership kick-off.