The UK Border Agency has confirmed the demonstrator on the roof of the Morton Hall centre in Swinderby near Lincoln is a detainee of the immigration centre.
"There is currently a peaceful protest ongoing at Morton Hall in which one detainee has scaled the roof.
"We are working with the Prison Service to resolve the situation."
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Sunny spells on Friday after a frosty start, with only isolated wintry showers, mainly over the hills. Cold with a brisk northerly wind.
Brisk northwesterly winds will bring scattered showers with some bright or sunny spells developing in between. A widespread frost overnight.
Arthur 'Bob' Gumbley was beaten and robbed in his own home before he died in hospital.