Nazir Afzal announced his resignation on his Twitter account, writing: 'Given media calls I confirm that I've resigned as Chief Executive of country's police & crime commissioners I'm not saying anything publicly'.
Given media calls I confirm that I've resigned as Chief Executive of country's police & crime commissioners— nazir afzal (@nazirafzal) May 30, 2017
I'm not saying anything publicly
But the BBC has claimed his departure was connected to a 'row over media coverage of terror attacks'.
The experienced lawyer oversaw a number of high profile convictions, including the Rochdale grooming gang and disgraced former BBC presenter Stuart Hall.
He also led the prosecutions of Coronation Street actors Bill Roache, who was cleared of rape, and Michael Le Vell, who was also acquitted of child sex abuse.
On the day of the Manchester Arena bombing which killed 22 people and injured dozens more, Mr Afzal tweeted: 'Manchester is my home now & my heart breaks for those who lives were taken These deluded narcissistic criminals never divide or defeat us. (sic).'
The following day, he tweeted: 'I prosecuted terrorists of all motivations. They're not soldiers. They're sad narcissists- thinking the world owes them. We owe them nothing.'
Alongside a photo of Manchester city centre, he wrote: 'Terrorists want us to change our lives because of them.They lose when we don't.'
Mr Afzal led the Crown Prosecution Service (CPS) in North West England from 2011 to 2015.
In 2015 Mr Afzal quit his role at the CPS after he was accused of sending a text message to a defendant.
An internal inquiry exonerated him but he nevertheless handed in his resignation as more senior colleagues insisted his departure is due to an 'on-going drive for efficiency'.
Mr Afzal proved himself to be an outspoken advocate of bringing to justice those accused of the most heinous and sometimes sensitive offences.
This included a move to overturn an earlier decision on an Asian Rochdale sex grooming ring that led to a series of convictions.
He said that an over-sensitivity to political correctness and 'fear of appearing racist' by 'white professionals' may have stalled justice.
More recently he was responsible for the successful conviction of disgraced former BBC presenter Stuart Hall.
Mr Afzal took up his post in 2011 and led a huge team of about 700 lawyers, legal staff, and administrators.
He was responsible for all criminal prosecutions across Greater Manchester, Lancashire, and Cumbria.
After studying law in Birmingham, Mr Afzal qualified as a solicitor and worked in private practice until he joined the CPS in 1991.
He began his CPS career in central London and has prosecuted and advised on many high profile cases.
Mr Afzal was awarded an OBE in the Queen's New Years Honours List in 2005 for his public service and involvement with the local community.