In a statement, the company said that around 40 cases have occurred since April 2020 onwards.

Removing oil from the transformer has the potential of severely damaging it, besides causing power outages, it said, adding that leaking oil from a transformer can also lead to a fire hazard.

BSES said that it has taken these incidents very seriously and registered FIRs in various police stations.

"More recently, oil thieves were caught red-handed while trying to steal the oil from a Distribution Transformer (DT) in Subhash Mohalla in east Delhi. They were handed over to the police and sent to Mandoli Jail. A similar case of oil theft was reported even last week from Lodhi Road," it said.

During the last few months, oil has been stolen from DTs located in several areas of south, west, east and central Delhi. In south and west Delhi, these pockets are located in Paschim Vihar, Punjabi Bagh, Palam, among others.

In east and central Delhi, these pockets are located in Mansarovar Park, Rani Jhansi Marg, GTB Enclave, Nand Nagri, Shastri Park among others.

Meanwhile, BSES is closely working with Delhi Police to crack down on this menace. It said that thieves are able to steal oil from live transformers, even when they are properly locked and surrounded by steel fencing.

Apart from taking assistance from Delhi Police, BSES is taking several measures to contain this menace including increased vigilance, especially during the night hours, cooperation of RWAs, deployment of quick response teams along with other steps.

A BSES spokesperson said, "These incidents of oil theft can cause a lot of inconvenience to the residents. We appeal to our consumers to be vigilant and if they or the colony security guards find anyone suspicious near an electricity substation/transformer, they should check the person's ID and immediately alert BRPL on 19123 or BYPL on 19122 or call police on 100. Let us join hands to fight this menace."