Thailand‘s lottery officials are investigating ticket agent practices that enabled a man to win the country’s largest ever jackpot.

A 75-year-old man recently won 180m baht (US $5.35m) after presenting 30 pairs of pre-printed tickets with the same winning numbers to the Government Lottery Office (GLO). The payout is triple the amount of the previous largest lottery payday.

GLO agents aren’t permitted to offer more than one pair of tickets with the same number, but this case apparently involved a bunch of agents who traded tickets among themselves until one agent was able to offer a 30-ticket bundle with the same numbers to the 75-year-old winner.

The GLO doesn’t intend to punish the lucky senior citizen but the Bangkok Post quoted GLO Director Maj Gen Chalongrat Nakartit saying the agents who traded the tickets that created the bundle could have their contracts revoked.