Using an improvised device comprising a pen, a fishing hook and sticky tape, a 34-year-old woman stole - from letter boxes - grocery vouchers meant for low-income Singaporeans totalling $450.

Asmah Isnin pleaded guilty last Friday to three counts of theft.

The Budget 2020 grocery vouchers, worth $150 a set, were meant for those living in one-or two-room Housing Board flats.

Early last October, Asmah received her set of grocery vouchers. A few days later, she peeked into the letter boxes at Block 124 Kim Tian Place and saw that one had two sets of vouchers. These belonged to a man and his wife, who had moved to another address.

Asmah, who was then working as a food delivery rider, improvised a contraption to retrieve the vouchers, which she subsequently used.

The man later called the Health Promotion Board to inquire about his vouchers. He was informed that they had been mailed to his old address and had been used. He then made a police report.

Asmah also stole grocery vouchers belonging to a resident at the housing block, who learnt after speaking to staff at Tiong Bahru Community Centre that her vouchers had been used. She made a police report on Oct 14 last year.

Asmah was traced through closed-circuit television footage and was arrested two days later.

Court documents state that no restitution has been made, and the victims have since applied for replacement vouchers.

In written submissions, Deputy Public Prosecutor Joseph Gwee urged the court to jail Asmah for at least 10 months. He highlighted her previous theft convictions, including one in 2015 when she stole an electric bicycle worth $1,300.

"The accused's antecedent record clearly evinces a pattern of offences without any sign or acknowledgement of contrition or remorse," said DPP Gwee, who also said there was premeditation and preparation in this case, as Asmah had used an improvised device.

She is expected to be sentenced on Feb 19. For each count of theft, Asmah can be jailed for up to three years and/or fined.