The New South Wales environment watchdog suspects more than 10 tonnes of material containing asbestos has been used at the Rozelle Parklands in Sydney’s inner west, and says it considers the discovery an “emergency”.

It has also been revealed the state's transport authority has blamed the Christmas holidays for taking seven days to test for the dangerous material near a children's playground after being tipped off by a member of the public.

The Rozelle Parklands will remain closed for at least six weeks after traces of the potentially cancer-causing material were discovered in the mulch of three newly landscaped garden beds.

"The EPA reasonably suspects there is more than 10 tonnes of material containing asbestos, being asbestos waste, that has been applied to land in an area of the premises and is causing land pollution," the final clean-up notice issued by the NSW EPA on January 15 states.

Further testing showed three additional positive samples in garden beds in the Rozelle precinct, Transport for NSW (TfNSW) revealed on Thursday.

Two of the samples were found near the Motorway Operations Centre, which is not open to the public, and the third located in the traffic light island at the intersection of Victoria Road and Terry Street.

TfNSW said 114 samples in total were taken from the parklands and surrounds, with 17 positive results showing traces of bonded asbestos so far.

Deadline for asbestos removal delivered

The parklands opened to the public in December 2023, forming part of the WestConnex tunnel project.

TfNSW contracted John Holland to build the Rozelle Interchange, which includes the recreation area.

The contractor will provide TfNSW with a draft remediation plan to remove the asbestos from the parklands and associated sites.

The NSW Environment Protection Authority claims tests conducted by both TfNSW and the contractor confirm mulch contains construction and demolition waste, and some samples include asbestos.

Investigations into whether the contaminated material has been used at any other locations and where it was sourced from are underway.

The EPA has ordered all mulch to be removed from the parklands by February 29 and it must produce evidence it is has been properly disposed of by March 7.

Week-long delay 'due to Christmas'

Yesterday it was revealed the parklands remained open to the public for more than a week after a member of the public altered TfNSW of possible asbestos.

TfNSW confirmed it received correspondence from someone on Tuesday, January 2, but the email did not reach the appropriate team until the following week on Monday, January 8.

"The email was sent to a general project inbox from the member of public," a department spokesperson said in a statement.

The toxic material was first discovered by a parent whose child brought home some mulch after playing in the park.

On Tuesday, January 9, a hygienist tested the material that had been collected by a member of the public and took their own samples – two of which returned positive results.

At 6am the following day, part of the park was fenced off before the media was alerted later that morning.

Inner West Mayor Darcy Byrne has demanded an independent investigation into how the contaminated material ended up in the park.

TfNSW has said preliminary investigations show the mulch was inspected at several stages during the project.

The material is considered low risk because it is non-friable, unless it is damaged or old.