A serial underwear thief has admitted to breaching Singapore's strict coronavirus lockdown to sneak into a backyard and try to purloin women's lingerie. 

Lee Chee Kin has stolen underwear from homes on at least 30 occasions since 2018 and police found more than 100 bras during a raid on his home last year, according to court documents.

The 39-year-old was on bail over previous charges of underwear theft last month when he snuck out of home and climbed into a backyard on the hunt for more intimates. 

He was spotted by the homeowner and arrested.

On Monday he admitted in court to breaking lockdown rules by leaving his residence without a good reason and failing to wear a mask outside, and also pleaded guilty to charges of theft and criminal trespass. 

A prosecutor told the court that Lee "would select bras and panties to steal based on their appearance.

"The accused used the stolen bras and panties for his own sexual gratification."

Lee, who will be sentenced at a later date, could face a jail term and hefty fine.

Singapore closed schools and workplaces and at the beginning of April after being hit by a second wave of virus cases. 

People were told to stay at home as much as possible, and only go out for essentials such as exercise and grocery shopping.