A gang of 15 teenagers brazenly shoplifted from a Melbourne Officeworks store and left 'cheering and dancing' while holding the stolen items above their heads.

Witness Chris, who chose to keep his surname anonymous, said he went to the South Yarra store in the city's southeast to buy a computer at 4.30pm on Saturday when he noticed the youths, aged 13 to 17, taking headphones and speakers from the shelves.

He said the teenagers, believed to be members of the notorious Apex gang, were dancing down the aisles and walked out cheering a minute later, setting off the store alarms.

'They certainly weren't walking around with their heads down - they were happily ransacking the shelves,' he told 3AW on Monday.

Witness Chris said he went to the South Yarra Officeworks (pictured) in the city's southeast at 4.30pm on Saturday when he saw the youths, aged 13 to 17, stealing from the shelves

'The staff just stood there, like myself, probably in shock at what they were witnessing'.

Chris said the teenagers, all of African descent, were all wearing hooded jumpers, but were 'confident' as they trawled the store.

He said after the gang left and police had been called, he asked a staff member whether it was the first incident they had at the store.

'She indicated it had happened a few times before and they were a soft target on the weekends with reduced staff,' he said.

Victoria police confirmed to Daily Mail Australia officers went to the store following reports a group of about 15 males were shoplifting.

A woman who heard Chris' account, said she was driving along Nepean Highway when she saw a similar group heading toward the Moorabbin Officeworks (picured)

Chris said the teenagers were dancing down the aisles and walked out cheering a minute later, setting off the store alarms (stock image)

A woman who heard Chris' account, said she was driving along Nepean Highway on the same day when she saw a similar group emerging from a house and heading toward the Moorabbin Officeworks.

Witness Julia said the group were milling out the front of the store, but 'nervously legged it' down Highett Road when they heard police sirens approaching.

There was reportedly another similar incident at the Officeworks in Chadstone, 17-kilometres from the city centre, on Saturday.

An Officeworks spokesperson confirmed there were 'incidents involving theft at four of its stores in the south-eastern suburbs of Melbourne on Saturday'.

'No Officeworks team members or customers were harmed and all affected stores remain open today with a heightened level of security,' a statement read.

'As the incidents are currently under police investigation, we are unable to provide further comment at this time'.

Witness Julia said the group were milling out the front of the Moorabbin store, but 'nervously legged it' down Highett Road (pictured) when they heard police sirens approaching