An unemployed man was jailed for three months on Wednesday for threatening to burn down a lawyer's office.

Joseph Cruz, 58, pleaded guilty to criminal intimidation by threatening lawyer Lim Bee Li, 28, who is with Optimus Chambers, over the phone between Dec 26 last year and Jan 13 that he would burn down her office.

A Community Court heard that late last year, Cruz had sought legal services from two lawyers, Mr Irving Choh and Ms Stephanie Looi, who had been working in RHT Taylor Wessing and subsequently joined Optimus.

Investigation showed that between Dec 26 and Jan 7, he made multiple harassing calls to Ms Lim's law firm as he was unhappy with the way the legal proceedings for his matters had been turning out.

During one of the calls, Ms Lim told Cruz that the two lawyers were not in the office to answer his calls. He then said to her: "I will burn your office''. Ms Lim felt threatened and afraid.

Cruz continued to call the law firm from Feb 27 to March 1 even after the two lawyers had stopped representing him. Ms Lim had picked up some of the calls in which Cruz had used insulting words on her.

Cruz, who said he was of ill health, apologised to the victim.