Jim Colwell was the acting chief constable of Devon and Cornwall Police until his suspension.
A former acting chief constable could face misconduct proceedings following an investigation by the police watchdog.
The Independent Office for Police Misconduct (IOPC) said there was evidence Jim Colwell, who was the former acting chief of Devon and Cornwall Police, had potentially breached the force’s “notifiable associations policy”.
Mr Colwell was suspended in November last year for alleged “professional standards breaches” over claims he used his work mobile phone to exchange messages of a “personal nature”.
However, the IOPC said Mr Colwell had no case to answer in relation to the allegation of gross misconduct.
It also found he did not breach standards in his handling of a force disciplinary matter, but concluded he did have a case to answer for “a potential breach of the force’s notifiable associations policy”.
“We found no case to answer in respect of either the alleged use of a work issue mobile phone to exchange personal messages without a policing purpose, or his conduct concerning the handling of a force disciplinary matter,” an IOPC spokesman said.
“Overall, we found no evidence to determine any gross misconduct, or any breach of professional standards for honesty and integrity.
“We did decide, the now deputy chief constable has a case to answer for misconduct in respect of a potential breach of the force’s notifiable associations policy.
“In our opinion there was sufficient evidence upon which a reasonable misconduct tribunal could find that his actions breached standards of professional behaviour for order and instructions, and conduct.
“It will be for a future misconduct meeting, arranged by the chief constable of Essex Police as the delegated appropriate authority, to determine whether misconduct is proven and any outcome.”
Mr Colwell was suspended by the Devon and Cornwall police and crime commissioner, Alison Hernandez, and made a mandatory referral to the IOPC.
He had been leading the force in the absence of Chief Constable Will Kerr who had been suspended over allegations of sexual offences.
Last month, prosecutors in Northern Ireland said Mr Kerr would not be prosecuted.
He remains suspended by Devon and Cornwall pending the outcome of a resumed IOPC investigation.
The force is currently being led by interim Chief Constable James Vaughan.
