They are the army of workers who man Facebook's front line, tasked with removing offensive and terror-related material from the internet giant's site.

But a Mail on Sunday investigation has discovered the multi-billion pound social networking site employs hundreds of young Filipinos – some with limited English skills – who work gruelling shifts and say they earn just £1.81 an hour.

They are forced to decide in seconds whether or not to delete videos, pictures and posts which are too graphic or violent.

Staff face being sacked if they fail to meet strict quotas that mean they have to assess hundreds of extreme posts every shift.

Facebook, which recorded profits of more than £4.7 billion in 2015, has come under fire for giving a platform to terrorists to spread their hateful propaganda.

Facebook employs hundreds of young Filipinos - some with limited English skills - to remove offensive and terror related material from the site

Last week, Theresa May demanded a crackdown on social media giants that refuse to co-operate on terror.

In the wake of the Manchester attack, handbooks imploring extremists to target concerts were found on the internet.

The army of moderators are part of Facebook's community standards team whose job is to police the site.

Users can report posts which break Facebook's rules because they promote terrorist activity or contain sexually explicit material.

Earlier this month, Facebook founder Mark Zuckerberg boasted that the firm – worth £345 billion – would be adding another 3,000 workers to the 4,500 moderators it already employs and pledged to 'improve the process for doing it quickly'.

The MoS found that Facebook outsources some its moderating work to staff in the Philippines employed through multinational professional services firm Accenture.

Many staff last less than 18 months in the stressful jobs, which see graduates from conservative, devoutly Catholic backgrounds exposed to endless streams of graphic images.

The young Filipinos, paid just £1.81 an hour, are forced to decide in seconds whether or not to delete videos, pictures and posts which are too graphic or violent

Five employees interviewed by the MoS said moderators at Accenture's Manila office earned starting monthly salaries of 24,000 pesos (£376) for a six-day week of eight-hour shifts.

It means they earn the equivalent of £1.81 an hour. After five months, salaries are said to increase to 29,000 pesos, the equivalent of £2.19 an hour.

One ex-manager who helped recruit Facebook moderators said staff were often traumatised by material.

'The moderators have to check posts that have been flagged up and make a snap judgement on whether they should be taken down.

'They can't spend more than a few seconds thinking about it. They have to fulfil a quota and if they're too slow they won't last in the job.'

Last night, Liberal Democrat leader Tim Farron said: 'In the wake of the Manchester attack, the public will simply not accept hugely profitable multinational companies failing to do their bit to keep the public safe.'

Accenture disputed the salary figures but failed to provide any alternative information. It said: 'We hire college graduates, experienced hires, provide intensive training and pay competitive wages.'

In the wake of the Manchester attack, handbooks imploring extremists to target concerts were found on the internet. Pictured: A sickening video purporting to show a jihadist celebrating the Manchester terror attack

Facebook said: 'We've built a global network of operations centres to work 24/7 so that we have people in the right country with the right language and cultural skills to review reports.

'We recognise this work can be difficult, which is why our contracts with partners stipulate that wellness and psychological support must be provided.

'We will be reviewing the services provided by Accenture to ensure they meet our standards.'