The issue was first reported in mid-May and several occasions there have been statements that the issue was nearly solved. But the warning signs have stayed up.
Guernsey Water water quality risk manager Margaret McGuinness said the problem continued to be investigated.
‘Guernsey Water was notified of sewage odours on 19 May and identified a cracked private sewer which was repaired very quickly,' she said.
'However, two days later a further issue was identified whereby pollution was entering the stream via an inlet, so our investigation was led further afield.'
Signage installed by Agriculture, Countryside & Land Management Services on 20 May states swimming is not advised until further notice, and requests children and dogs are kept away from the stream.
‘The stream water is being sampled daily by Guernsey Water. ACLMS is regularly testing the bathing water and will be able to advise when it can reopen. Due to the time it takes to allow all the pollution to pass through the groundwater the beach has had to remain closed.'
The Office for Environmental Health and Pollution Regulation referred queries about the problem to Guernsey Water.
Despite the warnings, many beach-goers, dog walkers and swimmers were enjoying the bay.
Daily sea swimmer Jess Hamon said: 'We heard about it ages ago and thought it would have been sorted out by now. I'm glad they've got something up to say it's there, but have they done anything about it?'
She said it had been so long she had forgotten about the pollution.
By swimming at low tide away from the stream, it was hoped the bulk was avoided.
'It's such a lovely spot, we wanted to see what it's like for ourselves - there were no smells, it's clear as anything.'
Helen Gallienne said: 'We're year round sea swimmers so that sign doesn't put us off. We washed our hands and sanitised after, and didn't put our heads under. Things like this happen at Cobo all the time and nobody pays any notice.'
Grace Dudiene went for a paddle and said the water was beautiful.
A Petit Bot Tea Room spokesperson said despite much communication with Guernsey Water and relevant States of Guernsey departments, they have not had answers as to how and when it will be resolved.