The order was contained in a memo on Monday from the Department of Operations, Force headquarters in Abuja.
It was signed by Austine Agbonlahor, an Assistant Inspector-General of Police.
The letter with Ref. No CB: 2002/DOPS/FHQ/ABJ/VOL/77/168, said the directive must be effected immediately.
Last week, Ajayi complained that Salami withdrew his security details.
He said the Police Commissioner was doing the bidding of Governor Rotimi Akeredolu.
Ajayi and Akeredolu have been at loggerheads for months.
The deputy has dumped the All Progressives Congress (APC) for the Peoples Democratic Party (PDP).
There are speculations that just like in Edo where Governor Godwin Obaseki left the APC to PDP, got a waiver and picked the governorship ticket, a similar scenario will play out in Ondo.