BUILDERS working on the £60m extension of an Oxford sports centre have been forced to change their plans after discovering great crested newts.

The amphibians were found by contractors at Oxford University's Iffley Road sports complex, where a £8.5m indoor sports hall is being built.

University officials said the discovery would not delay the work but they will instead change their construction schedule to work around the creatures.

This is because great crested newts are a protected species and it is a crime to deliberately kill, capture or disturb them.

University spokesman Matt Pickles added: "While our contractors were carrying out demolition work on the Iffley Road site, they came across a protected species of newt.

"We have alerted the relevant authorities, who will ensure the newts are safely moved.

"Whilst this action is being undertaken, work associated with the Acer Nethercott Sports Hall is still in progress, with plans being adjusted to ensure that the relevant environmental issues can be accommodated."

It is the second wildlife-related discovery at the sports centre site, after badger sets were found and relocated to neighbouring land owned by Christ Church.

Work started on the centre's £60m redevelopment last month, after planning permission was granted in 2012.

A report submitted to Oxford City Council four years ago raised the prospects newts may be found. It said: "The potential presence of amphibians, including great crested newts, cannot be discounted."

According to wildlife charity Froglife, great crested newts are the largest of Britain's native newt species.

During the breeding season males develop a jagged crest which has a break at the base of the tail and females take on a ‘bulky’ appearance.

Their discovery can halt bulldozers and trigger a complicated process to relocate them, which involves obtaining a special licence.

The relocation can last two years due to requirements to work around the freshwater creatures' spring and summer migration between land and water.

University officials were previously hoping to start work on the sports centre in 2015 and will be keen to avoid further delays.

The first phase, approved in detail last year, will see a new indoor sports hall built next to the iconic running track where Sir Roger Bannister broke the four-minute mile in 1954.

The sports hall has been named after Dr Acer Nethercott, the Beijing Olympics silver medallist and Oxford graduate who coxed the university to victory in the boat race three times. He died aged 35 in 2012 due to a brain tumour.

The university also plans to build an indoor tennis centre, rugby and rowing training centre, grandstand and indoor cricket academy at the Iffley Road site, as well as an eight-badminton-court sports hall with squash facilities.