GMP's troubled new computer system iOPS crashed again this afternoon, forcing call handlers to take details of crime reports on paper.
A number of the force's computer systems, including iOPS, suddenly failed at about 1.30pm today (Wednesday).
As police computer screens across the force went blank, bosses initially feared a power outage at a GMP building was the cause.
But engineers quickly realised it was an IT failure.
All systems were eventually restored at around 3.30pm.
But for two hours the IT crash resulted in 999 and non-emergency calls being taken down on paper, force bosses have confirmed.
Engineers are now trying to pin-point the cause of the failure.
A statement from Greater Manchester Police said: "A number of GMP's computer systems have been impacted this afternoon, including IOPS.
"Early investigation confirms it to be a temporary failure of underlying IT infrastructure.
"GMP worked with suppliers to restore normal services at the earliest opportunity - and systems are now back online.
"Tried and tested business continuity plans were activated, which ensured that service delivery to our communities was minimised."
GMP has been dogged by problems since it introduced its Integrated Operational Policing System (iOPS) at a cost of £27m in July last year, some 19 months behind schedule.
Her Majesty’s Inspectorate of Constabulary (HMIC) told the force earlier this year that issues with the IT system had exposed hundreds of vulnerable people to 'potential risk of harm'.
Following a series of M.E.N. exposes, the police watchdog went into GMP in October and November last year to look at the backlog of open crimes that had built up since the system had been introduced to assess the risk levels within the crime queues and the impact on the force.
They found a huge drop-off in referrals for vulnerable children and adults, as well as 'inconsistent' communication with council social services departments.
Last week, the police watchog published a highly critical report into GMP after another inspection revealed the force failed to record one in four reports of violent crimes while an estimated 80,000 crime reports per year were not being properly recorded on its systems, although iOPS was not specifically mentioned.
It also expressed concern about GMP's approach to domestic violence and child protection, as well as delayed, dropped and badly-planned investigations.
Zoe Billingham, who authored the report on behalf of Her Majesty’s Inspectorate of Constabulary and Fire and Rescue Services, told the M.E.N. that GMP were now one of the worst forces in the country for poor crime records
