When his dream of buying the Sacramento Kings was shattered three months ago Seattle investor Chris Hansen was gracious in defeat and offered Sacramento congratulations for keeping the team.

On Friday he was unmasked as the mystery donor behind the signature-gathering effort to force a public vote on the Kings' proposed downtown arena - an effort that could derail the arena and jeopardize the team's future in Sacramento once again.

Amid a lawsuit and a state investigation Hansen and an Orange County political action committee filed documents revealing Hansen contributed $100000 to the petition drive on June 21 - a month after the NBA board of governors vetoed his plan to buy the Kings and move them to Seattle.

Hansen apologized for the donation on Friday and said he wouldn't give the anti-arena effort any more money. But the revelation seemed likely to damage the petition drive - and Hansen's own efforts to bring the NBA back to Seattle.

The state Fair Political Political Practices Commission said Hansen's donation violated state law because disclosure came two weeks late.

The lapse was "at best negligent at worst purposeful behavior" said Gary Winuk enforcement chief at the FPPC. With a sophisticated businessman like Hansen "there really isn't a justification for not filing on time" Winuk said.

The revelation came one day after the FPPC sued Los Angeles law firm Loeb & Loeb which served as conduit for the donation demanding that the donor's name be disclosed. Winuk said the lawsuit will be dropped but Hansen and the Orange County PAC will continue to be investigated although the law firm probably is in the clear. Hansen and the PAC could be subject to fines Winuk said.

The stunning disclosure was the latest setback for the Sacramento group gamely trying to carry on with the petition drive. The group STOP has been hurt already by media reports about the secrecy behind the campaign's funding.

Some 1600 citizens who signed the petitions have submitted paperwork demanding to have their names removed. STOP or Sacramento Taxpayers Opposed to Pork needs 22000 valid signatures by December to force a vote next June on the proposed $258 million taxpayer subsidy.

With the Hansen disclosure STOP's problems continue to grow said local political consultant Rob Stutzman who isn't connected to either side of the debate.

"Now there is an obvious pall cast by this surreptitious outsider funding this campaign" Stutzman said. "That will give pause to Sacramento citizens (when asked) to sign the petition.

"They have burned through their money; they have a serious problem to complete the task" he added.

Added Joshua Wood of the pro-arena group DowntownArena.org: "I think it makes it a lot harder for them to say this is about a public vote. This is about STOP acting as vassals for Chris Hansen." Wood's group filed the complaint that spawned the FPPC's investigation.

A new arena to replace aging Sleep Train Arena is considered crucial to cementing the Kings' future in Sacramento. Even though the NBA killed the move to Seattle in May Commissioner David Stern has said the league could relocate the team if there's no new arena by 2017.

Hansen issued a statement late Friday apologizing for the donation adding he will no longer fund the petition drive.

He said he got "caught up (in) the heat of battle" amid signs that he was losing the tug-of-war over the Kings.

But Hansen's statement made no explanation of why he made the contribution three weeks after he had lost the fight.

"This is clearly a decision I regret" he said. "I wish the city of Sacramento and Kings fans the best in their efforts and they have my commitment not to have any involvement in their arena efforts in the future."