A Chinese national was jailed for nine months on Monday for stealing a passenger's hand-carry luggage on board an aircraft.

Liu Yanjun, 40, pleaded guilty to stealing a brown trolley bag containing clothes and documents from Mr Lim Hock Siong, 63, on board a Tiger Airways flight from Macau to Singapore on Oct 19.

A court heard that after boarding the plane in Macau, Mr Lim's daughter mistakenly placed the trolley bag and their other pieces of luggage into the overhead compartment above the seats one row behind where she and her parents sat.

They decided not to move their luggage as it would be too troublesome.

A flight attendant later saw Liu, who was seated three rows behind the Lims, trying to force open a piece of luggage at his seat.

She recognised the luggage as she had earlier helped the victim's daughter place it into the overhead compartment.

She then notified her chief attendant who stood behind Liu and saw him trying to fix the lock on the trolley bag but to no avail.

Liu subsequently turned around and was shocked to see the chief attendant. He placed the victim's trolley back into the overhead compartment and slept for the rest of the journey.

The chief attendant later checked with Mr Lim who confirmed that the trolley bag was indeed his. Mr Lim found that the seal sticker which was placed over the lock had been torn off and the zipper broken. The three-digit combination code had also been reset.

Liu was detained when the plane touched down at Changi Airport.

He could have been jailed for up to three years and/or fined for theft.