A man is under arrest and will be interviewed by police over a series of suspicious blazes at a suburban racecourse, including one damaging a heritage-listed grandstand.
The 51-year-old man is accused of lighting four fires at the Caulfield Racecourse grounds early on Tuesday morning.
But it was three grass fires at Attenborough Park in the southeast Melbourne beachside suburb of Mordialloc that led to his arrest at a nearby train station about 12.30pm.
Detective Sergeant Stuart Hough said police were not looking for any other suspects over the blazes and the man matches the description of a person captured on CCTV at the racecourse.
"It's been great work by police today and the local community," Det Sgt Hough told reporters.
"They spotted him, called it through to triple zero, and we were there quickly on the scene to arrest him."
The major blaze tore through the heritage Norman Robinson stand, resulting in damage that could be millions of dollars.
Police arson chemists are still examining the scene at the grandstand.
The man's last known address was at Wangaratta in northeast Victoria.
Det Sgt Hough said the man once lived in the area of the fires, but it was many years ago and he had no known links to the racecourse or racing industry.
He does have a history with police, but Det Sgt Hough would not comment on whether that included arson.
Fire Rescue Victoria incident controller Dennis Smith said the fire caused "significant damage" to the stand and originated in a bar on the first level.
"It is timber, so it burned pretty well, also there's a bar behind, The 1876 bar, that has also been impacted by this," he said.
"As far as the grandstands on either side, there is a little bit of water damage but no fire (damage) thankfully ... but that stand itself is significantly impacted.
“I’m not a builder but from what I’ve seen this morning the damage will be in the millions.”
Desperate efforts from 17 crews and more than 65 firefighters stopped the blaze spreading and it was brought under control about 7am.
One firefighter suffered a minor hand injury and was treated in hospital.
"There are a lot of residents around here, but thankfully the wind wasn't significant so it didn't really impact (the surrounding area) as much," Mr Smith said.
Melbourne Racing Club chairman John Kanga said contingency plans were in place, with a race meeting scheduled for Wednesday moved to Mornington.
"We are gutted as a club, but we are keen to rebuild," he said.
The damaged areas are among racegoers' favourites.
"Both bars are very well frequented ... I can assure (members) that we will rebuild it as good or if not better than what it was," he said.
A Melbourne Racing Club spokeswoman said the extent of the damage was being determined and investigators, surveyors and health officials were carrying out inspections on Tuesday afternoon.
The racecourse is in the middle of a $300 million redevelopment, first announced in 2019, including works to the Norman Robinson stand.
Melbourne Football Club also plans to build a training and administrative base at the racecourse by 2028.
In December, the MRC agreed to sell a $195 million parcel of land at the site to Mount Scopus Memorial College for the school to build a new campus.
