A grass fire that sent flames leaping up to 15 metres above Macarthur over the weekend may have been deliberately lit.

Fire crews were called to the end of Ebsworth Close about 2.10pm on Sunday, and arrived to find a fire stretching about 100 metres by 80 metres.

It took firefighters about 90 minutes to extinguish the fire, which reached a height of 15 metres. No property was damaged.

Police have now been called in to investigate after a pipe and a bottle containing fluid were found at the scene.

Anyone who may have witnessed suspicious activity or has any further information about the incident is urged to contact Crime Stoppers on 1800 333 000 or via the website. Information can be provided anonymously.