Four animal rights activists charged with trespassing at a Mornington Peninsula egg farm have breached their bail conditions by breaking into the same property overnight to protest against caging conditions.

Police were called to the Somerville Egg Farm in Moorooduc, south-east of Melbourne, at 5.30am today.

ALV president Patty Mark with fellow activists Felicity Andersen, Lisa Manning and Jo Osborne inside the farm. Credit:ALV

The Animal Liberation Victoria activists chained themselves to a ladder inside the far end of a shed housing up to 20,000 hens at 4.30am, claiming the hens were malnourished.

ALV president Patty Mark, 62, and three other activisits – Felicity Andersen, 37, Lisa Manning 40 and Jo Osborne, 40 – wore biohazard suits and masks during the break-in, but were later arrested and removed.