An infrastructure project near the spot in Madhyamgram where Babu Sen and his associates were riddled with bullets on Thursday has triggered a realty boom and mushrooming of bars and restaurants across large parts of the northern fringe of the city.

The 38-km-long Kalyani Expressway, that connects Belghoria in North 24-Parganas to Kalyani in Nadia, is being widened from two to four lanes.

In a state starved of development, this rare project has pitched land mafia and construction syndicates against one another, resulting in a spurt in crime. Babu Sen, police said, was very much a part of the rivalry.

The widening of the expressway started in the middle of 2013. Several hundred trees were felled and many water bodies filled to make room for the widening of the road.

The expansion will improve the connectivity of the areas in the northern fringe - such as Ghola, Sodepur, New Barrackpore and Sajirhat - with the airport and the rest of Calcutta.

Apart from sparking a big demand for landfill and construction material, the project also created a scramble for sale and purchase of land along the expressway, construction of highrises and mushrooming of bars in adjacent localities.

"Areas like Ghola, Sajirhat, Lenin Nagar, Muragacha Road and Khorer Math were hooch hubs for Calcutta and North and South 24-Parganas even till a few years ago. The widening of the expressway is turning these areas, within 25km of Calcutta and 10km of the airport, into semi-urban suburbs," said a developer who is building a residential project in one of these areas.

Property prices have nearly doubled over the past two years since the expansion of Kalyani Expressway started.

In 2012, apartments in Ghola, Sajirhat and New Barrackpore were being sold at a price varying between Rs 1,300 and Rs 1,600 a square foot. Now it varies between Rs 2,600 and Rs 3,200.

In 2010, land in the area was priced between Rs 1.5 lakh and Rs 2 lakh a cottah. Now it has crossed Rs 4 lakh.

But behind all the swank development, crime thrives.

The huge demand for landfill and construction material in the areas has led to a proliferation of syndicates, which include members from places as far as Barasat and New Town where construction activity has slowed down.

A builder Metro spoke to, who is developing three residential projects in Sajirhat, said more than 100 syndicates are active in the area, many of which are controlled by people in New Town, Rajarhat, Hatiara and Barasat.

"Development activities in the neighbouring areas such New Town and Barasat have slowed down. Many companies have suspended construction. As a result some big syndicates there are turning their attention to areas along Kalyani Expressway and adjacent pockets. Everyone wants a slice of the pie here," the developer said.

Rivalry between syndicates, which often take a violent turn, has ensured that the crime rate has kept pace with the realty prices.

"The pie is limited but more and more syndicates are joining in. Nobody wants to concede an inch or a rupee to another," said a syndicate member in New Town with business interests along Kalyani Expressway.

Babu Sen, who supplied landfill and construction material to construction sites in Ghola and Agarpara, was riding the crest of the construction boom. He preferred to be called an "entrepreneur" and not a promoter.

Police plead helplessness when asked about the worsening law and order situation on the northern fringe.

"We are helpless. Firstly, the syndicates enjoy patronage of the ruling party. We have instructions to look the other way. Secondly, even if we want we can't crack down on the syndicates because of the lack of personnel and vehicles. They travel in bikes and SUVs, carry sophisticated arms and have several men. We have rickety jeeps, outdated guns and very few officers," said an officer of Ghola police station.