The bones were found near Junction 9 of the motorway in Wednesbury on the evening of April 12.
Police have confirmed that officers were still trying to formally identify the deceased – after the remains were found in woodland.
At the time officers said they suspected the remains had been there "for some time".
In an update provided this week, a spokesman for West Midlands Police said: "The death is not being treated as suspicious, and we’re still trying to formally identify the deceased."
Forensic officers were seen searching an embankment on the Wednesbury side of Junction 9, close to a railway line and the River Tame when the remains were first discovered. The woodland searched by police was located between the motorway and Axeltree Way, around 100 yards away from KFC and Pizza Hut and half a mile away from IKEA.
Remains have been found left in undergrowth next to major West Midland motorways at least twice before in recent years.
In 2015 remains belonging to Oldbury man Surjit Takhar were found close to the M54 seven years after he disappeared.
And in 2010 remains were found in undergrowth on an embankment near Junction 2 of the M5 in Oldbury.
Anyone with information about the remains found in Wednesbury can call West Midlands Police on 101, quoting incident number 3826 of April 12.