The actor who crashed his jet ski into a small boat on the Chao Phraya River on Saturday night, killing two people, was allegedly not qualified to drive a jet ski.

The Marine Office on Monday issued an order banning use of the jet ski, which was legally registered, and called in Shindanai Sae Lim, 21, the jet ski rider at the time of the accident, and its owner to give their accounts of what happened.

They were also asked to bring documents, including the jet ski's registration papers and helmsman certificate.

However, it was reported that Shindanai does not have a helmsman certificate. As a result, he might have to pay up to 10,000 baht in fines, face a jail term of up to six months, or both. 

He was among a group of 11 people travelling on five jet skis to a pier in Chom Thong district in Bangkok when the accident occurred.

His girlfriend, 17, and her 41-year-old mother, were riding on his jet ski.

He said the accident happened because he could not see the boat crossing the river, as it had no lights, and the river in that location was very dark.

However, a social media user who knew the driver of the small boat said that the driver always used a headlamp.

The crash resulted in the 64-year-old driver and his 44-year-old passenger drowning.