This shocker came to light when locals submitted these power bills as proof for unique identification or Adhaar cards, being issued to all Indians.
"It hurts us. We are Hindustanis, not Pakistanis," says Haji Yakub, a local resident.
Another area here in Nalla Sopara which falls in Thane District is called Laden Nagar - a reference perhaps to the terrorist Osama Bin Laden.
The electricity bill of Ramzan Mohammad Hafiz, who resides in Sagar Welfare Society, states his address as Laden Nagar. He says he has complained several times, but with no results.
The papers he submitted in 2007 for the electricity connection for his home show his address as Laxmi Nagar - the actual name of the area.
"I have friends in Maharashtra State Electricity Board (MSEB). They laugh at me when I show them the bill," he says.
Mr Hafiz says there is a story why this patch between Santosh Nagar and the Western Express highway came to be called Chhota Pakistan. "There used to be tension between the builder mafia and the local police here. That's why the cops started calling it Chhota Pakistan," he says.
Chaya Patil, a local corporator, brought this shocking lapse of the electricity department to the attention of the collector.
"An electricity bill is the official document. Who is responsible for these bills that have Chhota Pakistan written in their address box? Why brand the locality just because it is dominated by Muslims?" she says.
Officials of the Maharashtra Electricity company - Mahavitaran - have no answer for this.
When NDTV tried to question Subhash Bodhre, an officer with the state electricity company, he said, "I have no right to speak. This connection is of 2007 and I don't know about it."
The State Minorities Commission has asked the MSEB to probe the "serious lapse" of terming the area Chhota Pakistan on its bills.
"This is a serious matter. Please inquire into it and inform the Commission about your findings," State Minority Commission Chairman Munaf Hakim said in a letter to the MSEB chief. "Let us know at what level did the directive to term the area as 'Chhota Pakistan' emanated," the letter said.