"Last month alone we caught about 2,000 cows," an official from the Municipal Corporation of Delhi (MCD), which presented the annual figures to the Delhi High Court last week, told AFP.
"We keep catching cows as they are constantly brought into the city," said the official, who declined to be named.
The court has repeatedly ordered Delhi authorities to clear the streets of the animals, which they say pose a threat to traffic as well as a health risk.
Many of the animals belong to dairy farmers who do not have space to house the cattle and thus let them wander at will.
"Our workers and vehicles have been attacked by dairy owners when they try to take the cows away," said the official.
The captured cows are sent to state-run shelters and then auctioned.
The MCD says it is in the process of relocating hundreds of dairies to a site earmarked for the purpose.
Animal welfare activists say the cows -- considered sacred by the Hindus -- live in terrible conditions.
"The courts keep issuing orders for the cows to be removed. But they do not address the problem of these dairies or how cows suffer when on the streets," said N.G Jayasimha, campaigns manager of People for Ethical Treatment of Animals (PETA).
The stray cows live off rubbish from open dumps, and often die after eating plastic bags.
"One post-mortem of a cow revealed 14 kilos (31 lbs) of plastic," Jayasimha said.
Cow slaughter is banned in most Indian states, but many captured animals are sent to states where the practice is allowed.
"The dairy, meat and leather industries exploit these animals," said Jayasimha.