A million-dollar lottery winner in California who handed $100 to a stranger at a convenience store said she accidentally also gave him a $260,000 lotto ticket.

Emily Leech, who won a $1 million jackpot with a ticket she bought from the Liquor & Tobacco store in Mountain View in January, said she was aiming for an act of kindness when she handed $100 to a stranger in line behind her at the store prior to Friday's Mega Millions drawing and she later realized she had also handed him her ticket, which later won $260,000, the San Jose Mercury News reported Tuesday.

Leach said the clerk at the store told her the man returned Saturday and said she had purchased the ticket for him.

The state lottery commission's security department said the matter is being investigated.

"She said she had the ticket in her hand and maybe it got mixed in with the money she gave this person," said Alex Traverso, a spokesman for the lottery commission. "They're going to look at the video and see if she's the one actually buying the ticket. If no one else is in the picture, that puts things firmly in her favor."

Lottery officials said the man still had not come forward to claim the winnings Monday.