Minister for Urban Development K.T. Rama Rao told the state legislative assembly that Larsen & Toubro (L&T) in its correspondence with the state government mentioned about the cost overrun.
He, however, said the government had not yet confirmed cost escalation or committed to bear the additional expenditure.
Billed as the world's biggest metro rail project in the Public Private Partnership (PPP) mode, it was taken up in 2012 at a cost of Rs 14,132 crore.
The minister did not give any figure but the revised project cost is estimated to be nearly Rs 19,000 crore. L&T has reportedly sought additional amount of Rs 3,756 crore from the state government.
The original construction period for the 71.16 km elevated metro ended in July this year but the project could not be completed due to various reasons and the developer was granted 17 month extension.
The entire project, barring 5 km stretch in the Old City and about 1 km stretch between Hitec city and Raidurg, is now likely to completed by the end of 2018.
The minister stated that the state government had allocated Rs 3,000 crore for land acquisition, shifting of utilities and other works relating the project and out of this Rs 2,240 crore was already spent.
The Centre is providing Rs 1,458 crore towards Viability Gap Funding (VGF) and out of this it has already released Rs 958 crore.
The first phase of 30 km is likely to be inaugurated by Prime Minister Narendra Modi on November 28.
"We are yet to receive confirmation from the Prime Minister's Office but it is expected any moment," said the minister.
The minister claimed that this would also be the first metro project in the country where 30-km stretch will be inaugurated in the first phase. He said no metro in the country began its operations with more than 11 km.
Rama Rao said a delegation of state government officials had recently visited Japan for the second phase of the Hyderabad Metro.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)