A group of suit-wearing BASE jumpers have left passers-by in the Perth CBD shocked by leaping off the top of one of the city's tallest buildings in broad daylight before parachuting down to a park below.

Key points: The group plunged from the 40-storey Exchange Tower on Tuesday morning

The group plunged from the 40-storey Exchange Tower on Tuesday morning Shocked witnesses said they could not believe what they were seeing

Shocked witnesses said they could not believe what they were seeing BASE jumpers have previously targeted Bluff Knoll in WA's south

The WA Police condemned the stunt in which three jumpers were filmed standing on the top of the 40-storey Exchange Tower about 8:30am on Tuesday, before leaping off and landing in a patch of grass.

A fourth man was also involved in the stunt but did not jump, with a police spokesman saying the group left the area together in a waiting vehicle.

"This type of behaviour is reckless and irresponsible and the WA Police force does not condone this type of behaviour," the spokesman said.

Police later said they had found the vehicle at a house in North Perth, and a 35-year-old Scarborough man would be summonsed to appear in court charged with trespass.

"Investigators continue to appeal for information from the public to identify the other three men," a police spokesman said.

A group of BASE jumpers have plunged off a building in the middle of the Perth CBD. ( Supplied )

WA Police Minister Michelle Roberts said the jumpers were "reckless and stupid".

"It could have cost any one of them their lives, it also could have cost someone on the ground their life as well," Ms Roberts said.

Witness says jumpers quickly fled the scene

Alex Bennett, who works on the ninth floor of a nearby building, said he was confused when he saw the jumpers.

"I was just doing my work and out of the corner of my eye I saw something strange," he said.

"I walked over to the window and saw one dude landing right here with a parachute and I was like, 'What the hell?'

"I kept looking and another two guys landed, and they just grabbed their chutes and kind of legged it around the corner."

Mr Bennet said the jumpers made a quick getaway.

One of the BASE jumpers lands in a park in the Perth CBD. ( Twitter: @Owie_K )

"There was a bunch of people around here just kind of looking around like 'what the hell is going on?', and yeah, they just like full-pace legged it across the road and then they were gone," he said.

Exchange Tower is one of the tallest buildings in the Perth CBD.

It houses several government and corporate tenants, including the WA offices of the Department of Foreign Affairs and Trade, and Commonwealth Parliamentary offices frequently used by WA politicians including Attorney-General Christian Porter and Finance Minister Mathias Cormann.

At 40 storeys, Exchange Tower is one of the tallest buildings in Perth's CBD. ( ABC News: James Carmody )

A spokesman for Exchange Tower would not comment on how the jumpers managed to gain access to the building's roof.

Ms Roberts said she understood the jumpers wore suits in order to blend in and gain access to the building.

Obviously there's some security issues at that building," she said.

"Clearly that building needs to have its security reviewed, particularly how people got onto the roof."

BASE jumping not new to WA

In 2014, two thrillseekers successfully completed two separate BASE jumps from the peak of Bluff Knoll in Western Australia's Stirling Ranges.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 3 minutes 39 seconds 3 m 39 s Base jumpers take off from WA's Bluff Knoll ( Andrew Collins and Chloe Papas )

The men jumped from one of the state's tallest peaks before flying at high speed to the ground using wingsuits.

Neither of the men were injured and the activity was not deemed illegal at the time, but the department that manages the area cautioned about the risk of "inappropriate" activity.

A BASE jumper was injured in 2015 when he jumped off the top of the Queens Riverside apartment building in Perth.

The jumper was one of three men who leaped from the top of the 25-storey building on Adelaide Terrace about 2:00am.

He was taken to Royal Perth Hospital and treated for leg injuries.

Extreme sport's fatal risks

In 2017 a West Australian man died while attempting a BASE jump in Italy and crashing into a mountain in the Trentino region.

Ben Dummett, 25, from Mandurah, south of Perth, had been in Europe for several months BASE jumping with friends.

Ben Dummett was an experienced sky diver. ( Supplied: Facebook )

The experienced skydiver had completed more than 300 jumps before his fatal plunge.

The Australian BASE Association has previously campaigned for more legal BASE jumps to be held in Australia to enable jumpers to gain experience and improve safety.