But MTR projects director Chew Tai-chong also said that underground rock strata at the terminus were at a level higher than expected and would therefore take longer to excavate. Progress was also slowed by boulders and uncharted utilities.

The performance centre was expected to be completed after 2018 as part of the second batch of facilities to open at the long-delayed cultural hub. Other facilities due to be ready in the same period include the Lyric Theatre and Medium Theatre I.

The delay is the second setback for the culture hub in a year. In June, Chief Secretary Carrie Lam Cheng Yuet-ngor said the completion of some facilities, including the performance centre, would be held up by a lack of funds.

The centre comprises three performance spaces with different designs and equipment, with 150, 250 and 400 seats. It is designed for dance, theatrical and multimedia performances.

It is understood that M+, the museum of visual culture due to open in 2017, should not be affected as it is above the existing Airport Express tunnel.

The MTR said it had been communicating with the cultural district authority and would hand the terminus site back to it once railway construction was completed. "At this stage, we can't see any delay in that," a spokeswoman said.

A spokeswoman for the cultural district authority said it would work with the MTR and the government to assess the impact of the railway delay on its plans.

Construction of the first building in the district - the Xiqu Centre for Chinese Opera - started in September, 15 years after the project was first proposed. It is due to be completed by 2016.

In June, Lam said the arts hub would include more flats and offices to avoid the need for more government funding as costs rose to more than HK$47 billion. She said there would be deviations from the master plan by British architect Norman Foster.

The idea of building a cluster of state-of-the-art performance venues on reclaimed land at West Kowloon was first touted in 1998.