Bradford Bulls have entered administration and face "extinction" if a buyer is not found within 10 days.
The Bulls announced in March they needed £1m to stay afloat and are thought to owe over £600,000 now.
Joint-administrator Brendan Guilfoyle said: "We have just 10 working days to save the club from liquidation because there are no funds to carry on longer.
"If anyone is interested in buying the Bulls we need to hear from them, this club is on the brink of extinction."
He added: "The directors made every effort to try to save the club within the 14-day timescale issued by the courts, but the moratorium ended on Monday without any potential buyer coming forward."
The Bulls, who are currently ninth in the Super League table, are one of the most decorated sides in English rugby league.
They have been crowned Super League champions four times, with their last victory coming in 2005, and won the Challenge Cup on five occasions.
Administration means the Rugby Football League is now likely to hand them a points deduction and this would almost certainly scupper their hopes of making the play-offs for the first time since 2008.
Guilfoyle admitted that the meeting he had held with the club's staff prior to the public announcement about going into administration had seen tempers flare.
"The position of the staff is that their wages were paid for June but there may be redundancies," he told BBC Radio Leeds.
"The meeting I held with the staff was very difficult and the longer it went on the greater the feeling of animosity there was towards the directors who were there.
"There's a general feeling of unhappiness but I hope they realise that by binding together they can demonstrate what a fantastic club this is."
Former acting chairman Stephen Coulby revealed the club was in a worse predicament when he came in in the middle of May than had been thought and this has put potential investors off.
"Within 24 hours of getting through the door we found the situation was worse than we had previously assumed," he said
"We ultimately came to a figure of £1.2m to keep the business running to next year.
"What people have been saying to us is why would they put in money now when they can't see the club benefiting to the extent they want."
It is understood Bradford currently owe £196,000 in PAYE tax for May and June, plus an outstanding VAT bill of £250,000 from the sale of the lease of Odsal to the RFL, while the monthly wage bill is over £200,000.
On 14 June it was revealed that the club could be forced to go into administration after being served with a winding-up petition by Her Majesty's Revenue and Customs over unpaid tax.
Bradford shocked the rugby league world in March when they announced that they needed to raise £1m to stay afloat after an impending tax bill and a changed banking lending arrangement left them short of money.
Having asked supporters to pledge £100 and carrying out a number of fundraising activities they were able to raise their initial target of £500,000.
Attempts to pull in further investments were unsuccessful and chairman Peter Hood stepped down last month after a series of disagreements with majority shareholder Chris Caisley.
Coulby admitted the club were at serious risk of going into administration at the start of June.
The Bulls become the third Super League side in three seasons to enter administration after Yorkshire rivals Wakefield faced similar difficulties last year and Welsh outfit Crusaders in 2010.
Crusaders were then liquidated in 2011, with Widnes Vikings taking their place in Super League.
Bulls forward Ian Sibbit said on Twitter: "Super League wouldn't be the same without Bradford Bulls. Let's hope our great club can be saved."
Current Super League licences are not up for renewal again until 2014 so the Bulls' place in the elite of the sport should be safe, assuming they can sort out their financial problems.