A police chief who oversaw a controversial investigation into the former prime minister Sir Edward Heath “has a case to answer” for alleged misconduct for providing an inaccurate account of how his phone was damaged, a police watchdog has found.

An investigation into Mike Veale, the former chief constable of Wiltshire police, was launched in January by the Independent Office for Police Conduct (IOPC), following anonymous claims that he had damaged his police-issued mobile phone to hide contacts with “various parties” during Operation Conifer, which looked into claims about the late prime minister, that were eventually dismissed.

The IOPC said on Monday there was no evidence that Veale, now the chief constable of Cleveland police, had deliberately damaged the phone in order to hide information, but it reprimanded him for telling colleagues that it had been dropped in a golf club car park and inadvertently run over.

He subsequently explained to IOPC investigators that the damage was caused when he swung a club at his golf bag in frustration after playing a poor shot during a round in September 2017.

The investigation – which resulted in a 28-page report - was launched after the IOPC last year received an anonymous typed letter alleging that Veale and an unnamed Conservative MP had collaborated in leaks about the investigation into alleged child abuse by Heath in an attempt to boost Veale’s profile.

The IOPC director, Catrin Evans, said that the policeman had volunteered to the watchdog’s investigators that he was embarrassed by his behaviour over a momentary loss of self-control on the golf course.

“However, chief constables are expected to promote ethical values, lead by personal example and act as ambassadors for the standards of professional behaviour,” she added. “That Mr Veale chose to give a different account to the truth, both verbally and in writing on several occasions and for some time, in our view amounted to a case to answer for misconduct relating to honesty and integrity.”

The IOPC’s report has been sent to Cleveland’s police and crime commissioner, who has agreed agreed that Veale will be subject to a management action plan, including an ongoing programme of professional development.

Veale said on Monday that he had been warned by confidantes and members of the public that he would face false allegations to tarnish his reputation during Operation Conifer.

Expressing regret, he said he had given a different account to colleagues about the damage to his phone to “avoid more unnecessary media attention and to spare my own obvious embarrassment for damaging my phone in such a ridiculous way and, most importantly, to ensure my colleagues were not aware of the pressure I was feeling at a time when I needed to be strong”.

Operation Conifer found that there was no reason to suspect Heath had carried out a string of sexual assaults, but said he would have been interviewed if he were still alive.