Transport Minister Rajendra Gupta, meanwhile, has asked transport commissioner S. Regunathan to submit a detailed report. Neither Gupta nor transport department officials, however, offered any comments on why little action had been taken so far if they were aware that ``the issue is deep-rooted and one of the biggest illegal businesses''.

The police department already has 18 teams patrolling the city to identify erring bus operators.

Regunathan said that the list of bus routes and areas, where the vehicles are illegally parked, has been drawn. He refused to add further details at this stage.

``Even the 18 teams which have been on the job for the past few months do not have any specific area where the raids are conducted. The spots are altered every day for more effective results,'' said Regunathan. Though exact figures are still unavailable, another official in the transport department ministry said that permits of at least 50 buses had been impounded so far.

The department, however, has no information on the number of such buses which have resumed operations. The Delhi transport department has also sought assistance from their counterparts in neighbouring states like UP, Rajasthan and Punjab for more information on long-distance private bus services. A similar request will be sent to the Delhi Police.

``The problem is not just with Delhi-registered vehicles leaving the city, said Regunathan, ``but also with that of in-coming buses from neighbouring states.''

Rajendra Gupta said: ``What Express Newsline has mentioned is only the tip of an iceberg. The issue is deep-rooted and is one of the biggest illegal businesses in the city.''

Even more worrying, according to him, are complaints that several transport department officials are hand in glove with bus operators.

``The way these buses are being run, is not permissible. And using permits on the pretext of transporting marriage parties is strictly prohibited,'' said Gupta.