TORONTO - Some office lottery pools are putting strict rules in place after seeing bitter disputes erupt over some recent Lotto Max jackpots.

While it can be tempting to rely on the honour system, many group players say they don't want to risk ruining work relationships over money.

And of course, no one wants to be shut out in case of a big win, they say.

"We wouldn't want to get shafted in the end," said Erin Marinangeli, 32, a data management worker whose Toronto office splits Lotto Max tickets every Friday.

"It's not so much that we don't trust each other, it's that we don't want it to come to that," she said Tuesday, referring to the tensions surrounding the last two groups to win large Lotto Max draws.

Ontario's lottery corporation is investigating group wins for two $50-million Lotto Max jackpots after additional claimants came forward.

The Ontario Lottery and Gaming Corp. said Monday it is delaying the payout to a group of factory workers who hold the winning ticket in Friday's draw because others are claiming part of the prize.

Just weeks earlier, a $50-million Lotto Max jackpot was won by a group of 19 office workers. The prize is still under dispute and has yet to be presented.

Lottery spokesman Tony Bitonti said he hopes recent cases will convince lottery groups to establish clear rules instead of relying on goodwill.

"There has to be clear communication within the group," Bitonti said.

"There are a lot of misunderstandings," especially about potential grey areas, such as what happens when someone is absent from work, he added.

The lottery corporation provides forms and guidelines for groups. For the most part, those who use the forms are paid "without issues," Bitonti said.

Justin Manlow, who works for a non-profit organization in Belleville, Ont., said his office pool started using the recommended forms last year after hearing about a disputed jackpot.

The pool, which just recently disbanded, never had any problems, Manlow said.

The forms helped the group enforce its "no pay, no play" rule, though sometimes people covered for sick colleagues, he said.

"This stuff needs to be addressed ahead of time," Manlow said. "Money gets the best of people."

Others come up with their own systems.

Marinangeli's office started its lottery pool a few weeks ago, setting up a thorough record-keeping protocol to track who plays each time and avoid any strife down the line, she said.

Each week, organizers keep a notebook of who's in and who's out, she said. Everyone gets a photocopy or scan of the ticket "in case it's disputed," she said.

"You all think that once we win, everything will be happy and wonderful and it won't matter, but it's a lot of money," she said. "Anyone could come along and dispute it if you don't have a backup somewhere."