Smart gates at many Metro Railway stations are malfunctioning, leading to long queues during rush hours.

A Metro official said that on any given day 30 per cent of the 280 automatic fare collection and passenger control systems - or smart gates - at the 24 stations developed snags and could not be operated.

The Metro authorities have blamed the agency hired to maintain the gates for the snag. Metro has assigned the task to a consortium led by Keltron, a government agency, which has in turn hired an agency for the upkeep.

Metro officials said "maintenance activities" were stopped on August 12.

Keltron officials claimed there were delays in payments which had led to the problems. "But now the issues have been sorted out and there are no problems anymore," a Keltron official said.

Thousands of commuters face problems daily to pass through the smart gates. Often the gates don't open even if tokens or smart cards are placed on the panels, leading to confusion and queues.

Metro has deployed people at the gates to help passengers facing such problems but often the only solution they can provide is asking the harassed commuters to use another gate.

"It's true that on any given day there are a number of failures in the gates. We also receive complaints from passengers as they are inconvenienced at the smart gates. Despite several reminders to the agency the failures are not attended on time," Indrani Banerjee, the spokesperson for Metro, said on Sunday. "This also leads to large queues at the gates during rush hours."

Sources said the authorities were planning to scrap the annual maintenance contract with the consortium led by the Thiruvananthapuram-based Keltron and set up an "in-house" team for maintenance. The members of the team will be sent to the Delhi Metro Rail Corporation for training.

The annual maintenance contract, which costs Metro Rs 2 crore, was awarded to the consortium five years ago. The consortium, whose other partner is Indra Sistemas SA of Spain, had provided the hardware for the smart gates, a Metro official said.

Metro had in 2011 made the smart gates operational and introduced Radio-Frequency Identification tokens.

Metro sources said 50 men had been hired for maintaining the gates. Officials alleged that these men were irregular throughout the year and did not turn up at all on days the footfall hit the roof, such as during the Puja.

"We have written several letters to Keltron and also told their Calcutta office verbally to regularise the maintenance work. But they have paid no heed to our pleas," alleged a Metro official.