Recent car thefts and carjackings are the work of "hardened", "risk-taking" criminals, and not Apex gang members, Victoria Police says.

Taskforce Tense detectives are investigating after a group attacked a man with a baseball bat and stole his car in South Yarra.

Michael Tallal, from Avondale Heights, said he was set upon by six males and hit on the head with the bat after pulling over on Toorak Road to send a text message about 2:00am.

Police said Mr Tallal's Mercedes was struck from behind by another car.

His stolen car was later used in an aggravated burglary at Valencia Court in Cranbourne, in Melbourne's outer south-east.

However, Assistant Commissioner Bob Hill shied away from linking the incident to the Apex gang.

The gang has its roots in Dandenong and was involved in petty crime which escalated to aggravated burglaries and armed robberies.

"We are providing this group with oxygen," he said.

"We are prompting this criminal enterprise for no particular reason.

"A lot of it is attributed to the Apex gang and I don't think it's warranted."

Police said over the past 12 months, it had become a common occurrence for criminals to break into people's homes and take keys for their luxury cars.

However, Assistant Commissioner Hill said the focus on Apex had led to other criminals latching onto the term despite only a loose connection.

"These are people who are hardened criminals who are putting our community in fear and operating in a loosely networked group," he said.

"They don't have a club house, they don't wear colours.

"This is a group of young people carrying out thrill-seeking behaviour, risk-taking behaviour, reliving their action heroes."

Assistant Commissioner Hill rejected the idea that carjackings were copycat crimes because aggravated burglaries to steal luxury cars was a worldwide problem.