Police have arrested Jonathan Dick in the Melbourne CBD this morning.
Police were called to a car park on the corner of Flinders Street and Hosier Lane shortly before 7.50am following reports two men had restrained a third man.
It's believed an assault occurred and all three parties suffered injuries.
The exact circumstances leading up to the incident are yet to be determined, however police believe at least one of the men is known to Jonathan Dick.
The 41-year-old was arrested in relation to the existing warrant for murder and has been conveyed to hospital under police guard.
The two other men are assisting with enquiries.
Anyone who witnessed the incident is urged to contact police via Crimestoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au
